Page 1 WORKSHOP MANUAL TRACTORS (T303HST/T353HST) #604-9, Namsan-dong, Changwon-city, Kyungnam, Korea ■ ■ ■ ■ TEL:82-55-279-4379, FAX:82-55-279-4447■ ■ ■ ■ www.tym.co.kr...
Page 2: Table Of Contents
HST TRACTOR T303HST/T353HST WORKSHOP MANUAL Chapter 1. Introduction ------------------------------------ Chapter 2. Disassembly and reassembly of major point ------ Chapter 3. Engine accessories ------------------------------------ Chapter 4. HST system --------------------------------------------- Chapter 5. Transmission ----------------------------------- Chapter 6. Front axle (4WD) --------------------------------- Chapter 7. Rear axle and Brakes --------------------------------- Chapter 8.
Page 3: Chapter 1. Introduction
Chapter 1 Introduction INTRODUCTION-------------------------------------------------------------- SAFETY INTRODUCTION------------------------------------------------- WARNING SIGNS IN THIS MANUAL---------------------------------- SAFETY SIGNS---------------------------------------------------------------- SAFETY DECALS----------------------------------------------------------- 1-11 UNIVERSAL SYMBOLS--------------------------------------------------- 1-14 SECTION 1. TRACTOR TYPES AND PUNCHED IDENTIFICATION MARKS ----------------------------- 1-15 SECTION 2. SPECIFICATIONS------------------------------------------ 1-17 SECTION 3. GEAR TRAIN DIAGRAMS------------------------------- 1-20 SECTION 4. PRECAUTIONS FOR TRACTOR OPERATIONS--- 1-21 1.
Page 4 Chapter 1 .Introduction This tractor Workshop manual is for qualified service personnel engaged in servicing and overhauling T303HST/T353HST tractor.Use of this publication is not recommended for field operators since they usually do not have access to special tools and shop equipment essential for most servicing.
Page 5 SAFETY INSTRUCTION ALWAYS PRACTICE SAFETY BY THINKING BEFORE ACTION AVOID FIRE HAZARDS. -Keep fire extinguishers easily available and in good operating condition. All relevant personnel should know how to operate fire fighting equipment. -Keep a first aid kit in an easily accessible location. -Do not smoke while handling fuel,or other highly flammable material.
Page 6 STAY CLEAR OF PTO 1) Entanglement in rotating drive line can cause serious injury or death. 2) Keep tractor master shield and drive line shield in place at all times except for special applications as directed in the implement operator's manual. 3) Wear fairly tight tight fitting clothing.Stop the engine and be sure PTO driveline is stopped before making adjustment,connections,or cleaning out PTO drive equipment.
Page 7: Warning Signs In This Manual
WARNING SIGNS IN THIS MANUAL The following warning symbols in this manual draw additional attention to items of importance for the safe and correct operation of the tractor. SIGN MEANING OF SIGN Serious hazard with a very high level of risk of either serious injury or death DANGER Hazard or unsafe practice that can lead to severe...
Page 8: Safety Signs
SAFETY SIGNS RECOGNIZE SAFETY INFORMATION This symbol, Safety-Alert Symbol, means ATTENTION! YOUR SAFETY IS INVOLVED. The message that follows the symbol contains important information about safety. Carefully read the message SIGNAL WORDS. A signal word―DANGER, WARNING OR CAUTION―is used DANGER with safety alert symbol.
Page 9 HANDLE FUEL SAFELY-AVOID FIRES Handle fuel with care; it is highly flammable. Do not refuel the Tractor while smoking or near open flame or sparks. Always stop engine before refueling Tractors. Always keep your tractor clean of accumulated grease, and debris.
Page 10 TRACTOR RUNAWAY 1.The tractor can start even if the transmission is engaged position causing Tractor to runaway and serious injury to the people standing nearby the tractor. For additional safety keep the pull to stop knob (fuel shut off control) in fully pulled out position. Transmission in neutral position, Foot brake engaged and PTO lever in disengaged position while attending to Safety Starter Switch or any other work on Tractor.
Page 11 USE OF ROPS AND SEAT BELT The Roll Over Protective Structure(ROPS) has been certified to industry and/or government standards. Any damage or alternation to the ROPS, mounting hard-ware, or seat belt voids the certification and will reduce or eliminate protection for the operator in the event of a roll-over.
Page 12 AVOID HIGH-PRESSURE FLUIDS Escaping fluid under pressure can penetrate the skin causing serious injury. Keep hands and body away from pinholes and nozzles, which eject fluids under high pressure. If ANY fluid is injected into the skin. Consult your doctor immediately. PREVENT BATTERY EXPLOSIONS Keep sparks, lighted matches, and open flame away from the top of battery.
Page 13: Safety Decals
SAFETY DECALS The following safety decals ARE INSTALLED ON THE MACHINE. If a decal become damaged,illegible or is on the machine,replace it.The decal part number is listed in the parts lists. WARNING ● Do not permit anyone but the operator to ●...
Page 14 WARNING WARNING KEEP HANDS AND CLOTHING The cooling system operates under pressure. ● ● ● ● It is dangerous to remove the radiator cap AWAY FROM ROTATING FAN AND BELTS TO PREVENT while the system is hot. ● ● ● ● Always turn the cap slowly to the first SERIOUS INJURY stop and allow pressure to escape before Location: On Radiator bracket side LH &...
Page 15 WARNING ● Start engine only from operators seat. If safety start switch is bypassed engine can start with transmission in gear. ● Do not connect or short across terminal on starter solenoid. Attach booster cables as shown on battery decal and operator’s manual. Starting in gear causing runaway can result in serious injury.
Page 16: Universal Symbols
UNIVERSAL SYMBOLS Some of the universal symbols have been shown below with an indication of their meaning Engine speed Pressured- Corrosive rev/minX100) open slowly substance Hours, Continuous ”Tortoise” recorded variable Slow or minimum Setting Engine ”Hare” fast or coolant Warning maximum temperature setting...
Page 17 SECTION 1. TRACTOR TYPES AND PUNCHED IDENTIFICATION MARKS The tractor serial number is shown on the left hand side of the tractor as shown in the picture. The engine number is stamped on the top of the engine block. Engine type and number on the R.H.S of Engine body Manufacturer’s tractor Sr.
Page 18 3.Engine model Identification and serial number Location. 1-16...
Page 19: Section 2. Specifications
T353HST - 26.5 / 2700rpm Number of Cylinder 1500cm / 1,758 cm Displacement T303HST - 78 mm X 78.5mm Bore and Stroke T353HST - 78 mm X 92mm T303SHT - 21.3± ± ± ± 0.5 Compression ratio T353HST - 24.3± ± ± ± 0.5...
Page 20 MODEL T303HST/T353HST Main Dry single disc, mechanic Clutch Multiple wet disk Dimensions Overall length(mm) 3337 (131.4”) Overall width (mm) 1635 (64.37”) Overall Height (mm) 2400 (94.49”) Wheel base (mm) 1100 (43.31”) (Distance between shafts) Min. Ground Clearance (mm) 323 (12.72”)
Page 21 MEMO 1-19...
Page 22: Section 3. Gear Train Diagrams
SECTION 3. GEAR TRAIN DIAGRAMS FIG.1-3 GEAR TRAIN DIAGRAM 1-20...
Page 23: Section 4. Precautions For Tractor Operations
SECTION 4. PRECAUTION FOR TRACTOR OPERATION 1. INSTRUMENTS Note; Oil pressure warning light and charge light on the monitor array will light when the main switch is Oil pressure warning light and charge light on the monitor array will light when the main switch is turned from OFF to ON - All lights on the panel go out automatically when the engine is started and its speed is increased to a specific level.
Page 24 MEMO 1-22...
Page 25: Controls
2.CONTROLS MONITOR LIGHT ARRAY High beam lamp Low beam lamp 4WD drive lamp PTO monitor Lamp fuel Glow signal Check lamp Cruise Control Oil pressure Parking brake Charge Lamp Lamp lamp lamp lamp 1-23...
Page 26: Filling Diagram And Capacity Table
3. FILLING DIAGRAM & CAPACITY TABLE TABLE 1-7 Filling point Fillings Quantity Liter (gal.) MODEL T303HST/T353HST RADIATOR 50/50 : Ethylene Glycol/Water (L.L.C) 7ℓ(1.85 US gal) ASTM D4985 / D6210 ENGINE API : CF-4 grades Above:25°C(77°F)… SAE30 or 15W/40 0°C to 25°C(32°F to 77°F)…...
Page 27: Maintenance Chart
4. MAINTENANCE CHART ○ inspection,replenish,and adjustment ● Replacement △ △ △ △ Cleaning and/or washing ☞ ENGINE ★ Consult your Dealer Inspection and servicing intervals Hour of operation Judgment Inspection (X10 on hour meter) Intervals after that criteria items mm(in) ○...
Page 28 ○ inspection,replenish,and adjustment ● Replacement △ △ △ △ Cleaning and/or washing ★ Consult your Dealer ☞ TRANSMISSION Inspection and servicing intervals Hour of operation Judgeement criteria Inspection (X10 on hour meter) Intervals after that mm(in) items ○ ● ● Transmission Replace after initial 50 Clean hydraulic...
Page 29 Inspection and servicing intervals Hour of operation Judgment criteria Inspection (X10 on hour meter) Intervals after that mm(in) items Electric All should work Parentheses properly Adjusting Check after 300 accelerator ★ hours ★ pedal and throttle lever Oil leaks in Check every year by clutch removing the plug...
Page 30 Chapter 2 Disassembly and reassembly of major components SECTION 1. GENERAL PRECAUTIONS AND SEPARATION AND REINSTALLATION --------------------------------- 1. Before operation ------------------------------------------------- 2. Precautions to be followed when installing standardized parts. ----------------------------- SECTION 2. OPERATION CHART FOR DISASSEMBLY AND REASSEMBLY BY MAJOR BLOCKS------------ SECTION 3.
Page 31: Before Operation
5) Installed bearings should turn smoothly. 9) When replacing parts,use authorized, (2) Oil seals genuine TYM parts only.TYM assumes no 1) Oil seals installer should be responsibility for accidents,operating designed so as not to deform the oil problems or damage caused by the use of seals.
Page 32 2) During installation,be careful not to damage (5) Spring(roll) pins the lips,and assure that it is pushed in parallel to the shaft or hole. 1) Spring pins should be driven in properly as tightly. 2) Spring pins should be installed so that their 3) When oil seals are installed,there should be seams should face the direction from which the no turnover of the lips nor dislocation of the...
Page 33 ,Be sure to wind the wire paying sufficient 4) Each contact surface should be coated with an attention to its winding direction and bend the adhesive (THREE BOND TB 1215) and lock washer for secure looking. tightened evenly with bolts. Adhesive coated surfaces should be installed 4) When locking bolts and nuts with an within 30 minutes after application of the...
Page 34: Section 2. Operation Chart For Disassembly
SECTION 2. OPERATION CHART FOR DISASSEMBLY AND REASSEMBLY BY MAJOR BLOCKS •Power steering •Center pivot Front Axle •Air cleaner Axle Bracket •Final case •Radiator •Differential gear •Oil cooler •Engine front parts Engine •Muffler Front •HST UNIT Transmission Space transmission •Flow-Divider •PTO Clutch •HST control linkage •HST control linkage...
Page 35: Section 3. Separation Of Major Components
SECTION 3. SEPARATION OF MAJOR COMPONENTS 1.SEPARATION OF THE FRONT Note: AXLE AND AXLE BRACKET When working on the 4WD version,the drive shaft should be removed ahead of time. Parts which can be inspected during This operation -Center pivot -Final case -Differential gear (1) Removal 1) Hold the front hitch or the front bracket...
Page 36: Separation Of The Engine And Front Axle Bracket
2.SEPARATION OF THE ENGINE AND THE FRONT AXLE BRACKET 5) Open the front grille. Parts which can be inspected during This 6) Detach the head light wiring. operation 7) Remove the other wiring -Air cleaner 8) Remove the inlet pipe from the air cleaner. -Radiator 9) Remove the air cleaner.
Page 37: Separation Of The Engine And Front Transmission
Fig.2-11 Oil cooler and HST unit 13) Remove the battery and battery bracket. 8) Connect the wiring of the head lights and 14) Remove the two hoses for the power other harness. steering system. 9) Connect the ground strap and the battery cables. 15) Remove the mounting bolts of the right 10) Install the engine hood.
Page 38 FIG.2-14 4) Disconnect the panel instrument set removing bolts(4 nos.) FIG.2-13 2) Support the engine on the bottom with a jack or stands. 3) Hold the transmission with a garage jack or a crane so that the transmission side can be moved when needed.
Page 39 6) Disconnect the hydraulic hose from the power steering (orbitrol) Note: - Disconnect the linear shift control cable - Disconnect the cable from both the steering lever side and transmission. 7) Remove the mounting bolts and dismounting the dash panel FIG.2-17 8) Wedge both sides of the front axle to prevent the engine from tilting.
Page 40 8) Disconnect the rubber hose from the suction pipe. (2) Engine separation from the chassis. When separating the engine from the chassis, the following steps are required as well as the ones mentioned above. FIG.2-20 suction pipe. 1) Lift the engine with the hoist and hold 1) Lift the engine with the hoist and hold the front axle bracket with a stands or the like.
Page 41 (3) INSTALLATION REASSEMBLY IN REVERSE ORDER OF REMOVAL. 1) Install the engine on the front axle bracket. 2) Retightening the right hand pivot metal tightening bolts. 3) Connect hoses. 4) Assemble the engine and the front transmission. Note: - Apply small mount of grease to each of the sliding parts.
Page 42 4.SEPARATION OF THE FRONT TRANSMISSION AND SPACER TRANSMISSION 7) Remove the slow-return check valve knob Parts which can be inspected during This operation -HST unit -PTO clutch 1) Removal A:Removal of the whole floor. 1) Remove the side covers(LH and RH). 2) Disconnect the negative battery cable.
Page 43 10) Remove the parking brake. 11) Remove the main shift and transmission range shift levers.The levers can be separated in the middle. 12) Remove the control rods of the PTO shift and 4WD shift levers from the transmission. 13) Remove the position control levers. FIG.2-28 Rubber mounting 17) Lift up the floor slightly with a hoist.
Page 44 20) Lift the floor gradually taking care not to allow 3) Disconnect the brake rods. the shaft of the slow return check valve and its hole in the floor to interfere with each other. Slow return check valve Brake rod. FIG.2-34 Brake rod.
Page 45 5) Remove the suction and delivery pipes. 6) Remove the delivery pipe for the PTO clutch. 7) Remove the 4WD shift metal FIG.2-37 PTO Clutch (7) Install the front wheel drive shaft. FIG.2-36 4WD shift metal (8) Position the floor taking care not to allow wiring or other parts to be pinched under it 8) Remove the HST unit from the front (9) With the floor lifted up a little, install the fuel...
Page 46 5.SEPARATION OF THE SPACER TRANSMISSION AND REAR TRANSMISSION (8) Remove the operator’s seat Parts which can be inspected during This operation (9) remove the position control lever -Drive pinion gear (10) Remove the lever guide. - Speed range gear (Transmission range shift) (11) When the tractor is equipped with an optional - HST control linkage.
Page 47 (27) Remove magnetic cruise. (20) Remove two rubber mounts. (28) Remove MID PTO stopper assembly Rubber mounting bolts FIG.2-44 Frame rubber mounts. (21) Lift up the rear end of the floor/fender assembly by about 10 mm,and place wood between the spacer transmission case and floor FIG.2-47 magnetic cruise panel (22) Drain the transmission of oil...
Page 48: Separation Of The Rear Transmission And Rear Axle Housing
6.SEPARATION OF THE REAR (32) Remove all the spacer-rear transmission case tightening bolts and nuts except the TRANSMISSION AND REAR AXLE bottom bolt. HOUSING Parts which can be inspected during This operation - Diff Lock - Brakes - Brake cases - Final gears - MID PTO gears.
Page 49 (4) Remove the brake rods. (5) Remove the 3-point linkage and related parts. FIG.2-53 3-point linkage FIG.2-55 Brake (6) Support the floor panel with a trestle or the 2) Installation like. Reassemble in reverse order of disassembly. (7) Remove the rubber mount along with the (1)Install the brake (LH and RH) bracket.
Page 50: Separation Of The Rear Transmission And Mid Pto
7.SEPARATION OF THE REAR TRANSMISSION AND MID PTO GEARS (15) Detach the MID PTO case assembly from Parts which can be inspected during This operation the rear transmission. -MID PTO gears. Inspection and service of the rear transmission should be performed following the instructions in the paragraph : 5 SEPARATION OF THE REAR TRANSMISSION AND SPACER TRANSMISSION...
Page 51: Separation Of The Rear Transmission And Cylinder Case
8.SEPARATION OF THE REAR TRANSMISSION AND CYLINDER CASE (10) Detach the delivery pipe from the cylinder Parts which can be inspected during This operation case. - Control valve (12) Remove the slow-return check valve along - Control linkage with the shaft. - Piston and lift crank linkage (13) Remove the 3-point lift link and related parts from the lift arm.
Page 52 Chapter 3 ENGINE ACCESSORIES SECTION 1. RADIATOR --------------------------------------------------- 1. General description ------------------------------------------------------ 2. Radiator -------------------------------------------------------------------------------------------- 3. Specifications ------------------------------------------------------------------------------------ 4. Removal of the radiator ------------------------------------------------------------------- 5. Inspection of each part -------------------------------------------------------------------- 6. Radiator reassembly ------------------------------------------------------ 7. Daily inspection ----------------------------------------------------------- 8. Trouble shooting ---------------------------------------------------------- SECTION 2.
Page 53: Section 1. Radiator
Chapter 3.Engine accessories SECTION 1. RADIATOR 1.General description The pressure cooling system includes mainly the radiator,water pump,multi-blade fan, and the thermostat.During the warm-up period,the thermostat remains closed and coolant is directed through by-pass to the suction side of the water pump.
Page 54: Radiator
2. Radiator The radiator consists of radiator cores, a tank to Flow coolant,side plates to install the radiator, and a fan guide. Fin-tube type cores are used and the cores and tank is made of anti corrosive aluminum and aluminum alloy. FIG.3-3...
Page 55: Specifications
3. SPECIFICATIONS Description T303HST/T353HST Radiator core type Flat water tube with corrugate fins Core train number 4 trains Radiator fin pitch 4.2 mm 9.3044㎡㎡㎡㎡ Thermal radiator area 0.9±0.15Kgf/ ㎠ Pressure valve opening pressure Coolant capacity 7 ℓ(contains in cylinder block) Test pressure 0.9±0.15 Kgf/㎠...
Page 56 -Clean with a detergent When cleaning the radiator with a detergent, follow the instructions given by its manufacturer. Different detergents have different characteristics. b. Cleaning the radiator exterior Cleaning the net (wire mesh) After the tractor has been operated in dusty FIG.3-5 conditions,check the net daily and clean it if necessary.
Page 57: Radiator Reassembly
6. RADIATOR REASSEMBLY 0.9 Kgf/ ㎠ Pressure valve Reassemble the radiator in the reverse order of Opening pressure (12.79 psi) disassembly. 0.04-0.05 Kgf/ ㎠ Vacuum valve Note: Opening pressure (0.57-0.71psi) - The rubber hoses should be clamped securely and must not interfere with the cooling fan. -Function test: - The radiator cores must not interfere with the The pressure type radiator cap has a pressure valve...
Page 58: Trouble Shooting
8. TROUBLE SHOOTING TABLE 3-1 Problems Causes Countermeasures 1) Overheating (1) Low coolant level (1)Replenish coolant and inspect water leaks. (2) Fatigued pressure valve spring (2)Replace radiator cap. (3) Loose or broken fan belt (3)Adjust belt tension or replace. (4) Oily fan belt (4)Replace.
Page 59: Section 2. Air Cleaner System
SECTION 2. AIR CLEANING SYSTEM 1.GENERAL DESCRIPTION Unfiltered air contains many particles harmful to the engine such as dust ,sand,or other foreign matter. When such foreign matter have entered in to the engine,They have mixed into the lubricant and promote wear of lubrication parts in addition to damaging the piston cylinders.To eliminate these harmful particles,an air cleaner has been installed.The air cleaner Which is installed on the T series tractor is a dry,cyclone type and is constructed as shown in the figure.
Page 60 2.ELEMENT AIR CLEANER (1) SPECIFICATIONS. Model T303HST/T353HST Type Dry, paper element filtering type 4.25(150) Rated intake air volume(㎥/min .(cu.ft/min) Air venting resistance (㎜Aq) 120 or less Cyclone efficiency (%) 45 or over Total filtering efficiency(%) 99.9 or over Dust holding capacity (gr) Filtering area (㎡)(sq.in)
Page 61: Inspection Of Each Part
Note: 3. INSPECTION OF EACH PART Especially note the glue portions of the paper and 1) Inspection of the cleaner body metal parts. (1) Check the cleaner exterior for cracks, deformation,or damage and repair or replace 4. CLEANING THE AIR CLEANER if necessary.
Page 62: Element Installation
-After soaking,rise it in fresh water. -Let it in a shaded and well ventilated place. Forced drying by heat or compressed air is prohibited. Note: Water applied to rinse the element should not have a pressure of more than 2.8kgf/㎠㎠㎠㎠ (39.8psi).
Page 63: Chapter 4. Hst System
CHAPTER 4 HST system SECTION 1. SPECIFICATIONS------------------------------------------ Special or essential tools ------------------------------------------------------------- 2. Other materials ------------------------------------------------------------------------- SECTION 2. COMPONENT LOCATION------------------------------- Hydraulic hoses and lines ------------------------------------------------------------ 2. Hydrostatic transmission ------------------------------------------------------------- 3. Transmission main pump case------------------------------------------------------- 4. Transmission back plate and motor------------------------------------------------ 5.
Page 64: Section 1. Specifications
SECTION 1. SPECIFICATIONS General Hydraulic Reservoir Capacity----------------------------------------------------------------35ℓ (9.24 us gal) Pump or motor Roller Bearing( From back plate to Top surface of bearing)------- --------------------------------------------------------------------- 2.3 mm± ± ± ± 0.2 mm(0.090 ±0.010 in) Roller Bearing in Motor Housing(Recess From Top of Counter bore) ---------------- -------------------------------------------------------------------- 2.0 mm±...
Page 65: Special Or Essential Tools
1.SPECIAL OR ESSENTIAL TOOLS. Note; Order tools according to information given in the U.S SERVICE-GARD ™ Catalogue or in the European Microfiche Tool Catalogue(MTC) Parts number parts name JT07335-1,2,3 Splitting Standard and Brackets JT03344 2,000 Kpa(300 psi) Gauge JT03362 68947KPa (10,000 psi) Gauge JT03364 Hose with quick coupler JT03017...
Page 66: Section 2. Component Location
SECTION 2. COMPONENT LOCATION 1.Hydraulic Hoses and lines. 1.hydraulic oil cooler 2. Gear pump 3. Cooler return Line 4. Steering Control Unit 5. Hydrostatic Unit...
Page 67: Hydrostatic Transmission
2.Hydrostatic transmission 1. Input shaft From engine 7. Charge pressure relief Valve 2. Control Lever 8. Filter mount port 3. Back Plate 9. For,&Rev.Relief valves 4.Hydrostatic motor 10. Hydrostatic pump...
Page 68: Transmission Main Pump Case
3. Transmission main pump case 1. Cap screws (6) 2. Washers(6) 3. Cover 4. Seal 5. O-ring 6. Bearing 7. Shims 8. Housing 9. Cam plate 10. Cam washer 11. Rotating Assembly 12.Valve plate 13. Bearing(4) 14. O-ring 15. Cover 16.
Page 69: Transmission Back Plate And Motor
4. Transmission back plate and motor 1.Bearing 2.Gasket 3. Pin 4. Pin 5.back plate 6. Cap screw 7.Bearing 8.plug and O-ring 10.Spring 11. Poppet 12.Spring 13. Plunger 14.poppet 15.Spring 16.Shims 17. O-ring 18.Plug 19.Filter head 20. O-ring 21.Relief valves,Forward and reverse 22.
Page 70: Hydrostatic Control Linkage
5.Hydrostatic control linkage 1.Holder comp 17.bolt 33.Bolt 2.Bolt 18.Arm comp 34.Nut 3.Washer spring 19.Arm comp 35.plate,forward 4.Washer plain 20.Plate reverse 36.Bolt 5.Nut 21.Washer plain 37.pin,oil damper 6.Rod comp 22.pin,split 38.Washer spring 7.Nut 23.Arm,cam 39.Damper oil 8.Nut 24.Arm,cam 40.Bolt 9.Elbow,LH 25.Bush(20X23X20) 41.Washer plain 10.Elbow,RH 26.Bolt...
Page 71: Hydrostatic System Schematic
6-1. Hydrostatic system schematic...
Page 72 6-2. Hydrostatic system schematic...
Page 73: Section 3. Troubleshooting
SECTION 3. TROUBLESHOOTING Problem or symptom Check or Solution Check flex plate coupling between • engine and pump Hydraulic level low in transaxle • • • Low charge pressure (see Tests and • • • Adjustments Section) Main drive pressure relief valve stuck •...
Page 74: Section 4. Diagnostics
SECTION 4. DIAGNOSTICS Test conditions: - Operator in seat - Key switch in RUN position Test/Check point Normal If Not normal 1. Control pedals Pedal should move freely Check linkage from pedals to pump Test conditions: - Start engine and run at slow idle Test/Check point Normal If Not normal...
Page 75: Section 5. Theory Of Operation
SECTION 5. THEORY OF OPERATION HYDROSTATIC SYSTEM Function: Charge pump The charge pump is a gear type positive The hydrostatic system provides a means to transfer displacement pump mounted to the right front Power from the engine to the final final drive to the side of the engine.
Page 76: Section 6.Tests And Adjustments
SECTION 6. TESTS AND ADJUSTMENT 1.HYDROSTATIC PEDAL AND NEUTRAL ADJUSTMENT Reason: To ensure that tractor does not move unless forward or reverse pedal is depressed. Procedure: 1.Operate the hydrostatic control pedals.They should return by themselves to the neutral position.If pedals do not operate properly,check pedals and linkage for damage or wear.
Page 77: Hydrostatic Pump Pressure Test
2. HYDROSTATIC PUMP 4.Start engine and run until hydraulic oil is PRESSURE TEST warm. 5.Stop engine Reason: 6.Cycle all controls to relieve any pressure To ensure that internal parts of the hydrostatic pump that may be in the hydraulic system are not worn excessively,and the relief valves are operating properly.
Page 78: Charge Pump Pressure Test
13.Slowly depress forward directional pedal and Procedure: observe gauge.Gauge should slowly rise to 1.Park tractor on a level surface and set park approximately 41368 KPa± ± ± ± 1378KPa brake. (6000psi ±200psi)and relief valve will 2.Turn key switch to OFF position. open with an audible squealing noise.
Page 79: Hydraulic System Bleed Procedure
4. HYDRAULIC SYSTEM BLEED PROCEDURE Reason: To remove air trapped in the hydraulic system which will prevent proper operation. Procedure: IMPORTANT: If contamination is found in hydraulic system filter or inside reservoir,flush entire hydraulic system. NOTE: Fill the hydraulic oil filter with new oil before installing.
Page 80: Section 7.Repair
SECTION 7. REPAIR 1.TRACTOR SPLITTING (FRONT) Note: It is not necessary to remove the flywheel housing from the engine unless engine is being removed.Split the tractor between the tunnel and flywheel housing as outlined in the story below. Prepare the Tractor: 1.Remove any mid or front attachments and mid .
Page 81 All electrical connectors attaching wiring harness switches and lights on rear half of tractor. All electrical connectors attaching wiring harness switches and lights on front half of tractor. 4-18...
Page 82 17.Disconnect lower brake rods at rear brake levers. 18.Remove turnbuckle at front of lower brake rods, and remove brake rods from tractor Turn buckle Brake rod. Magnetic cruise 19.Disconnect hydraulic pressure tube at lower Left side of Transmission 22.Disconnect hydraulic supply tube at SCV or manifold block,Remove tube.
Page 83 24.Remove hydraulic filter. 28.Disconnect switch connector 25.Disconnect two hydraulic charge pressure tubes from hydrostatic transmission 26.Loosen hose clamp and disconnect suction tube from manifold. 29 .Remove 5 screws connecting tunnel to flywheel housing.Note length and location of screws when removing. IMPORTANT: Check for ,and disconnect any additional accessory wires or hydraulic tubes connecting rear half to front half before...
Page 84 Assemble Tractor Sections. NOTE:Splines on all drive shafts and couplers 6.Connect suction tube to manifold.Tighten hose must be aligned before tractor sections clamp are bolted together. 1.Align splines on hydrostatic transmission drive shaft and engine fly wheel. 2.Move tractor sections together and retain with 5 screws.Tighten bolts to 90-110N.m.
Page 85 10. Install hydraulic supply tube to tractor. Connect hydraulic supply tube to SCV. Tighten tube nut to 55-79N.m(40-59lb-ft). 14.Connect lower brakes rods to rear brake levers.Retain with turn buckle and nuts. 11.Connect hydraulic pressure tube at lower Left side of Transmission Turn buckle Turn buckle Brake rod.
Page 86 18.Connect four work port tubes to SCV. NOTE: Drive shaft may come out with Tighten tube nuts to 40-57N.m(30-43 lb-ft). transmission.If removed with 19.Connect battery negative terminal. transmission,remove from 20. Install fenders. transmission,and install into tunnel and 21.Install seat and seat platform range transmission.
Page 87: Hydrostatic Transmission Disassembly
3.HYDROSTATIC TRANSMISSION Gasket DISASSEMBLY Cap screws Hydrostatic pump 4. Remove gasket from pump assembly. Hydrostatic motor Back plate Disassembly: IMPORTANT: The pump body and motor Motor valve plate body are aluminum and can be easily Spring pin damaged by steel tools.Be careful to not Dowel pin damage machined surfaces.Do not use screw driver or other sharp objects to pry...
Page 88 7.Mark the forward and reverse relief valves and IMPORTANT:To avoid damage to needle bearings their ports to ensure they go into the correct holes When removing or installing,press only against during assembly.Remove the relief valves from side of bearing with lettering. the back plate.Clean the relief valves in a suitable When removing bearings from the back plate,be solvent,and check for damaged springs or seats.
Page 89: Hydraulic Pump
8. If the bearings were removed from the back plate,press new ones into position using a suitable bearing driver.The numbers on the NOTE: If neutral adjustment cap screw is bearing should face the outside of the back loosened,neutral adjustment procedure must be plate.press the bearing in until 2.3±0.2 mm performed.see “HYDRAULIC PEDAL AND (0.09in ±0.010in) of the race remains...
Page 90 2. Remove cap screw and nut.Remove speed The following parts will be needed to disassemble control lever and neutral switch as an assembly. the piston block. 2ea------------3/8 IDX1-1/4 in .OD flat washers. 1ea------------3/8X 5in.N.C. cap screw Gasket 1ea------------3/8 in .N.C.nut 1ea------------1/2 in.Drive Socket with 1-1/8 in.OD Hydrostatic pump...
Page 91 12.Remove washers,springs,pins,and pin retainer. 1.Remove three cap screws and shaft end cap. 13.Inspect parts for wear or damage.Replace if 2.Remove three cap screws and pain end cap. needed. Shaft removal and Disassembly: Bearing cone Seal Internal snap ring 3.Remove bearing cones from both ends of the control shaft.Inspect bearing cones for smooth operation,wear,or damage.Replace parts as 1.Remove the internal snap ring retaining the...
Page 92: Hydrostatic Pump Inspection
thrust plate Wear surface 8. Remove thrust plate. 2.Inspect the piston block surface that makes contact with the valve plate.This surface should be smooth and free of deep scratches. needle bearing 3.Check the piston movement in the block bore.If the pistons are sticky in the bore,examine the bore for scoring or contamination.
Page 93: Hydrostatic Pump Assembly
2. Apply a small amount of grease to back of 9.Inspect the shaft for damage on the bearing thrust plate and install thrust plate into cam surfaces or in the splined areas. plate. 10.Inspect thrust bearing and washers for wear. 11.Inspect the servo piston for scratched and wear.
Page 94 IMPORTANT:Old O-rings,gaskets,and seals IMPORTANT:Old O-rings,gaskets,and seals 10.install the external snap ring,thrust washer, will leak.Always install new O-rings, will leak.Always install new O-rings, and thrust bearing on the shaft.install the gaskets, and seals during assembly. gaskets, and seals during assembly. outside thrust washer and external snap ring. 11.Install the washer and a new seal onto the shaft.
Page 95: Hydrostatic Motor Disassembly
13.Apply a small amount of grease to the Pivot Shoe face steel side of the valve plate to hold it in Spider place during pump installation. 14.Install pump valve plate on back plate. 15.Place a new gasket on the pump. 9.Place an appropriate size socket in the hole in the piston block to keep the pivot in place while installing the pistons.Slide the...
Page 96 Motor valve plate Spring pin Dowel pin NOTE: pump and motor valve plates are very similar in appearance,but are not interchangeable.Note shape of valve plates when removing.Valve plates are not fastened to back plate,but may 3. Remove cam washer from back of motor adhere slightly because of oil between housing.
Page 97 3. Inspect the bronze side of the valve plate for ear,Replace the valve plate if any wear,scoring,or scratches exist. 4.Inspect the piston block surface that makes contact with the valve plate. This surface should be smooth and free of deep scratches.
Page 98: Hydrostatic Motor Assembly
11.Inspect the cam washer shoe surface.It 14.Screw the nut on and slightly compress the spring should be free of scratches and wear marks. inside the piston block. 15.Use retaining ring pliers to remove the internal IMPORTANT: Piston face damage can be retaining ring.
Page 99 1. If the bearings were removed from the back 4.Apply some grease to the “THIS SIDE plate, a new one can be pressed in,Numbers DOWN” side of the cam washer before up,using the correct size bearing driver. installing into motor housing so it will stay in The back plate bearing should be pressed in place while installing rotating assembly.
Page 100 13.if removed,install the spring pin in the Pivot Shoe face Spider back plate used to retain the valve plate. Allow the pin to protrude from the back plate approximately 4.4mm(0.17 in) 14.If removed, install two dowel pins. 15.Apply a small amount of grease to the steel side of valve plate to hold it in place for installation.Place the valve plate in position on the back plate with steel side...
Page 101 CHAPTER 5 Transmission SECTION 1.GENERAL DESCRIPTION----------------------------------- 1.Wheel driving system--------------------------------------------------------- 2.PTO drive system ------------------------------------------------------------- 3.Power train diagrams -------------------------------------------------------- SECTION 2. SPECIFICATIONS-------------------------------------------- 1. Wheel drive system --------------------------------------------------------- 2. PTO drive system ----------------------------------------------------------- SECTION 3.DISASSEMBLY,INSPECTION,AND REASSEMBLY-- 1. HST system and change gear(front transmission)--------------------- 2.Mid transmission case-------------------------------------------------------- 1) PTO Input gear------------------------------------------------------------ 2) PTO counter shaft---------------------------------------------------------...
Page 102: Section 1.General Description
Chapter 5 .Transmission SECTION 1.GENERAL DESCRIPTION 1. WHEEL DRIVE SYSTEM The wheel driving system is composed of the following major components: Damper Front transmission Transmission Change gears Mid transmission Front drive change gears PTO Clutch MID PTO change gears Rear transmission REAR PTO change gears Fig.5-1 Wheel drive system 2.
Page 103: Section 2. Specifications
SECTION 2. SPECIFICATIONS 1. WHEEL DRIVE SYSTEM T303HST/T353HST Speed shift range Engine rated rpm: 2800 rpm Main speed shift Speed range shift L(Low) 0.3250 (13/40) Reduction M(Mid) 0.6061 (20/33) ratio H(High) 1.3182 (29/22) Drive pinion-Wheel gear 0.0363 (10/51*10/54) Operation Main speed shift...
Page 104: Hst System And Change Gear(Front Transmission)
DISASSEMBLY SECTION 3. ,INSPECTION,AND REASSEMBLY 1.HST system and change gears (front transmission). Fig.5-2 1. Input shaft From engine 7. Charge pressure relief Valve 2. Control Lever 8. Filter mount port 3. Back Plate 9. For,&Rev.Relief valves 4.Hydrostatic Motor 10. Hydrostatic pump...
Page 105 1.1 Disassembly. (1) Removal of HST system and related parts. Separate the engine from the front transmission referring to the paragraph of SECTION 7. REPAIR in CHAPTER 4. 1.HST Unit 2.Hydraulic filter 3.Valve 4.Pin,hollow 5.6.7.8.9 Bolt, hex Fig.5-3 1.Shaft PTO Clutch 2.Gear,helical 35T 3.Bearing,Ball 4.Bearing,Ball...
Page 106 1-2. REASSEMBLY Reassemble them in reverse order of disassembly in accordance with the following instruction. - Installation of clutch damper and related parts. (1) When installing the clutch damper on the flywheel,be sure to install the cotter pin to flywheel. (2) Apply a thin coat of molybdenum disulfide-based grease(Three bond TB1901 or equivalent) to revolving or sliding parts prior to reassembly.
Page 107 2. MID TRANSMISSION 1) PTO INPUT GEAR SUB ASS’Y 1.Gear helical 21T 2.Bearing,Ball Fig.5-6 (1) Pay attention to the direction of installation and check to see all the parts turns smoothly. (2) When pushing the RBB’s (6205)in to the gear,be careful only to push their inner races. (3) When installing the PTO Clutch assembly,Apply a thin coat of grease to the seal rings and install it taking care not to damage these rings.
Page 108 3) PTO CLUTCH (3-1) DISASSEMBLY PTO BRAKE Fig.5-8 1.Shaft,PTO clutch 2.Bearing ball(6203) 3.Collar(26x35x03) 4.Bearing ball 5.Gear,helical 35T 5.Gear,helical 35T 6.Bearing,ball 6.Bearing,ball 7.Clutch ass’y PTO 7.Clutch ass’y PTO Note: Disassembly of the PTO clutch assembly should be done in a clean,dust-free place.Exercise special attention to avoid damage of the seal rings,etc a.
Page 109 -Inspection for disc thickness and serration wear. Inspection Items Specified values Usable limit Disc thickness 2.2±0.1mm 1.9mm (0.087 in) (0.075 in) Surface flatness 0.2mm (0.008 in) Fig.5-11 e. If the combined thickness of the return plate and brake disc deviates from the specified value, replace both parts.
Page 110 (3-3) REASSEMBLY Fig.5-13 Reassemble the parts in reverse order of disassembly,following these instructions. Note: -Each parts should be washed clean before c. When installing the return spring,use a reassembly. special tool; the snap ring should be securely -Apply multi-purpose,quality grease to -Apply multi-purpose,quality grease to seated in the groove.
Page 111 HST REASSEMBLY 1.HST Unit 2.Pin,Hollow 3.Case,Mid transmission 4.Washer,spring 5.6.7.8.Bolt,hex Fig.5-16 Fig.5-16 Reassemble them in reverse order of disassembly in accordance with the following instruction. - Installation of clutch damper and related parts. (1) When installing the clutch damper on the flywheel ,be sure to install the cotter pin to flywheel.
Page 112: Mid Transmission Case
(4-1). Forward and reverse 1) HST holder comp 1.HST Unit 2.Bolt 3.Washer spring 4.Washer plain 5.Holder comp 6.Nut (1) When reassembling holder comp, take care directions. (2) After installing holder comp,be sure not to skip the parts. Fig.5-17 2) ROD Assembly 2) ROD Assembly (1) Install the pin on Mid transmission case.
Page 113 3) Forward and reverse arm assembly (1)when assembling the forward and reverse arm to pin ,be sure to apply grease. (2) Snap ring should be seated securely in it’s groove with the press- processed side turned towards the outer side. (3) Full grease after assembling the nipple.
Page 114: Mid Pto Stopper
5) MID PTO STOPPER ASSEMBLY 1.Bracket comp,actuator Fig.5-21 2.Washer spring 3. Nut 4.Bolt 5.Washer spring 6.Actuator comp,MID PTO 7.Elbow 8.Hose ,300MID PTO 9.Adapter MID PTO Lever 5-13...
Page 115: Mid Pto Stopper Operation
6) MID PTO STOPPER OPERATION Fig.5-22 ① When PTO switch is ON at engine works,The hydraulic fluid of PTO Valve flows to PTO clutch through hydraulic pipe,and let PTO shaft rotate which is engaged to Gear(16/23). ② The fluid flows to actuator and piston operates to protrude. ③...
Page 116 3. Rear transmission case Fig.5-23 5-15...
Page 117 3-1. DISASSEMBLY Separate the spacer transmission and the rear transmission from each other and then remove the hydraulic cylinder case.referring to paragraph 7.(1) of SECTION 4. SEPARATION OF MAJOR COMPONENTS in Chapter 2. (1) Ring gear,Drive pinion,and related parts. Fig.5-24 1.Mid PTO case 2 Pinion,drive 10 3.
Page 118 a. Disconnect Mid PTO case by loosening bolts f. Pull out diff pinion shaft(18) and take out dif- as shown in Fig.5-25 pinions(17) and dif-side gears(15). g. Remove the pinion metal(support) tightening bolts and take put drive pinion and related parts as an assembly.The number of installed shims should be written down or memorized for later reference.
Page 119 (2) PTO shaft and related parts. Fig.5-29 1.Gear,spur12 2.R.B.B(6305) 3.C-ring,shaft 4.R.B.B(6205) 5.Gear spur,14 6.C-ring,shaft 7.C-ring,hole 8.Seal 62 9.Shaft,PTO 10.C-ring,shaft 11.R.B.B(6205) 12.Gear,spur 37 13.Collar(35X50X2) 14.R.B.B(6207) 15.C-ring(hole) 16.Oil seal 17.Cover 18.Bolt 19.Hook,rear PTO 20.Lever,rear PTO 21.Stay,PTO shift 22.Shifter,PTO Low speed a.Remove the rear hitch and the trailer hitch b.Extract PTO shaft stay(21) rearwards and take out shifter(22).
Page 120 3-2. INSPECTION Before and after disassembly,inspect each part for the items mentioned below.Parts which deviate from the specified values should be replaced. -Wash clean all disassembled parts and check them for wear,damage,deformation,Burning ,etc. Defective parts should be corrected or replaced. Fig.5-30 -As the drive pinion and the ring gear make a pair,they (1) Drive pinion...
Page 121 When the drive pinion or the ring gear has been Ring gear tightening 9.0-11 Kgf.m replaced, the proper number of shims to be installed should be determined based upon the torque (39.8-69 ft.lbs) following procedure: Note: Drive pinion metal 5.5-7 Kgf.m - As shown in Fig5-34,there are two kinds of tightening torque (39.8-69 ft.lbs)
Page 122 Note: When reassembling the used pinion and ring gear,reinstall the same thickness of shims as was installed before disassembly in each shimming position. h.Backlash adjustment between the drive pinion and the ring pair(Fig5-35) i.As the drive pinion and the ring gear make a pair,be sure not to mate them with other parts from differential tractors.
Page 123 Note: Strike the circumference of the ring gear both sides with a copper hammer by turning the ring gear manually,and check to see that the backlash remains unchanged.The backlash should be checked at four points 90 degrees apart to each other. ⅲ...
Page 124 (2) PTO shaft and related parts. a.Pushing the PTO counter gear end into the bearing until the stop on the gear is securely seated against the bearing.The seal should be coated with an adhesive (THREE BOND TB1215) on the circumference before installing. b.Install the oil seal on the PTO shaft,paying attention to its installed direction.
Page 125: Shifter And Related Parts
4. SHIFTERS AND RELATED PARTS. 4.1. CONSTRUCTION (1) Forward and reverse control linkage mechanism. Fig.5-39 1.Holder comp 17.bolt 33.Bolt 2.Bolt 18.Arm comp 34.Nut 3.Washer spring 19.Arm comp 35.plate,forward 4.Washer plain 20.Plate reverse 36.Bolt 5.Nut 21.Washer plain 37.pin,oil damper 6.Rod comp 22.pin,split 38.Washer spring 7.Nut...
Page 126 Fig.5-40 (2) range shifter (Speed range shift) mechanism 1. Fork,range 2. Stay,range shift 3. Spring,shifter 4. Ball,steel 5. E-ring 6. Hook,range 7. O-ring (P) 7. O-ring (P) 8. Plate 9. Bolt(M8X16) 10. Washer plane 11. Arm,sub range 12. Pin,Taper split Note: The bottom two tightening bolts should be coated with an adhesive on their threads before being...
Page 127 (3) Front drive change (4 WD shaft) mechanism 1.Shaft,4WD drive 2.Gear,spur 28T 3.C-ring(shaft) 4.Bearing,ball(6204) 5.Bearing,ball(6004) 6.C-ring(hole) 7.Oil seal 8.Boss 9.Spring, shifter 10.Ball steel 11.Arm comp 12.O-ring(P) 13.Arm comp,shift 14.pin 15.Bolt(M8X20) Fig.5-43 Fig.5-44 5-26...
Page 128 (4) Rear PTO mechanism Shift stay PTO shaft Fig.5-45 Counter shaft 1.Gear,spur12 2.R.B.B(6305) 3.C-ring,shaft 4.R.B.B(6205) 5.Gear spur,14 6.C-ring,shaft 6.C-ring,shaft 7.C-ring,hole 8.Seal 62 9.Shaft,PTO 10.C-ring,shaft 11.R.B.B(6205) 12.Gear,spur 37 13.Collar(35X50X2) 14.R.B.B(6207) 15.C-ring(hole) 16.Oil seal 17.Cover 18.Bolt 19.Hook,rear PTO 20.Lever,rear PTO 21.Stay,PTO shift 22.Shifter,PTO Low Fig.5-46 speed...
Page 129 - REAR PTO counter shaft Fig.5-48 1.Gear,spur 12 2.Gear spur 14 3. Snap ring(shaft) 4. Ball bearing(6205) 5. Ball bearing(6305) Note: - When pushing the R.B.B’s(6305,6205) into the gear ,spur 12,be careful only to push their inner races. - The snap ring C should be securely seated in the groove and the press-processed side turned towards the outer side.
Page 130 (5) MID PTO (5-1) MID PTO CASE ASSY Fig.5-51 1. Case,Mid PTO 13.needle roller bearing 24.Bolt 2. plug square. (KT202417) 25.Bolt 3. Bearing ball(6203) 14.gear,spur 23-16 26.Washer 4. Shaft,MID PTO 15.Spacer 27.Boss 5. Bearing ball(6004HL1) 16. C-ring 28.Spring,shifter 6. Washer(20X30X1.8) 17.
Page 131 (5-2) MID PTO CASE SUB ASSY 1.case MID PTO 2. Bearing,Ball(6203) 3. Plug Fig.5-52 Note: When pushing the R.B.B’s(6203) into the CASE,be careful only to push their outer races. (5-3) Gear (spur/25) sub assy. 1Gear,spur 25T 2.snap-ring(hole) 2.snap-ring(hole) 3.Bearing,Ball(6203) Note: When pushing the R.B.B’s(6203) into the gear, Fig.5-53 be careful only to push their outer races.
Page 132 (5-5) MID PTO shift metal SUB 1.Boss 2. Spring shift 3.Steel ball 4.Arm comp 5.O-ring 6.Arm comp MID PTO shift 7.Spring pin Fig.5-55 Note: (1) When installing arm comp(6),take care not to mix the longer dimension . (2) When installing the O-ring,take care not to damage it or allow it to fall. (3) After installation,The Arm comp(shift) should slide with the designated grooves.
Page 133 6) Drive pinion Sub assembly 1..Metal pinion 2.Taper roller bearing 3.pinion drive 10 4.Taper roller bearing 5.Gear spur 23T 6.Nut(M30X1.5) 7.Washer(28X46X03) 8.Needle bearing 9.gear spur 40T 10.Hub(28X51X59) 11.Snap ring (shaft) 12.Gear spur 33T 13.gear helical 22T 14.needle bearing 15.Washer(20X34X03) 16.Ball bearing Fig.5-56 17.Washer(20X30X1.8) 18.Snap ring (shaft)
Page 134 Note: a.Apply oil to the drive pinion and related parts ahead of time.Then install them and tighten the assembly to the specified torque. b.Be sure that the starting torque of the drive pinion meets the specified level. Starting torque is 8-11 Kgf.m (0.08-0.11KN.cm) c.After the starting torque has been adjusted to the specified level,crimp the lock of the nut at one point as illustrated.
Page 135 8.Differential gears. Fig.5-58 1.Bevel 10X51 2.Case Diff(L) 3.Gear bevel(20) 5.Thrust collar,pinion 6.pinion Diff(12) 7.Shaft diff pinion 8.Case Diff (R) 9.plate lock 10.Bolt,differential 11.Nut 12.Ball bearing(6011) Differential gears and related parts Note: 1.When assembling without replacing the pinion gear and ring gear with new ones,provide the same shimming thickness as that provided before disassembly.
Page 136 6. PRECAUTIONS FOR DISASSEMBLY, INSPECTION,AND ASSEMBLY (1) Disassembly When drawing a shifter stay from its shifter,be careful not to lose the steel ball.It can jump out of the shifter. (2) Inspection -Shifter –disengaging load: Main change and sub change:18-22 Kgf (40-49lbs) 4WD change:25-29 kgf (55-64 lbs) -Usable limit of shifter-disengaging load: Main change &...
Page 137 SECTION 4. TROUBLESHOOTING 1. WHEEL DRIVE SYSTEM Problems Causes Countermeasures Transmission makes Insufficient or improper lubricant Replenish or replace noise in neutral Excessive splines of change shaft,spline hub,etc Replace Worn or broken bearings Replace Slide couplings interfering with the gears due to worn Replace or deformed shifters Gears make a noise...
Page 138 2. PTO DRIVE SYSTEM problem Causes Counter measures PTO does not spin with PTO PTO shift lever is in neutral Shift lever positively to shifted to ON Defective PTO switch replace Clogged PTO valve Wash clean Poor Pump Replace Defective solenoid valve Replace PTO spins but does not Worn clutch disc...
Page 139 Fig.5-60 5-38...
Page 140: Section 4.Trouble Shooting
CHAPTER 6 FRONT AXLE CHAPTER 6. FRONT AXLE(4WD)----------------------------------------- SECTION 1.GENERAL DESCRIPTION----------------------------------- SECTION 2. SPECIFICATIONS--------------------------------------------- SECTION 3.DISASSEMBLY,INSPECTION,AND REASSEMBLY-- 1. Center pivot ----------------------------------------------------------------- 1-1. Disassembly -------------------------------------------------------------- 1-2. Inspection ---------------------------------------------------------------- 1-3. Reassembly -------------------------------------------------------------- 2. Front differential ---------------------------------------------------------- 2-1. Disassembly -------------------------------------------------------------- 2-2. Inspection ---------------------------------------------------------------- 2-2.
Page 141 Chapter 6 Front axle(4WD) 1. GENERAL DESCRIPTION The 4WD front axle is a center pivot type.The front wheel drive mechanism is incorporated as a part of the axle. The front wheel drive power is taken off the rear transmission and transmitted to the differential in the front axle where the power is divided into right and left and to the respective final cases.
Page 142: Section 2. Specifications
SECTION 2. SPECIFICATIONS T303HST/T353HST Wheel alignment Toe-in (mm) Camber 3°± 1° Caster 3°± 1° Front axle Pivot metal (F) bore (mm) Φ55 Pivot metal (R) bore (mm) Φ80 Pivot metal (F) bush (mm) 50X55X20 Pivot metal (R) bush (mm) 75X80X30 Housing (F) Diameter (mm) Φ50...
Page 143: Section 3.Disassembly,Inspection,And Reassembly
SECTION 3. DISASSEMBLY,INSPECTION,AND REASSEMBLY 1. CENTER PIVOT Fig.6-3 1.Housing,front axle 10.Bolt (M16X40) 19.O-ring(G 55) 2.Oil cap 11.Washer,spring(M16) 20.Bolt 3.Plug 12.O-ring(P) 21.Nut 4.connector 13.O-ring 22.Seal washer 5.Hose(820) 14.Spacer (R) 23.Bolt(M12X40) 6.Clamp,(worm/14.5) 16.Metal pivot(F) 24.Washer spring 8.Metal,pivot(R) 17.Bush(50X55X20) 25.Washer 9.Bush(75X80X30) 18.Spacer (F)
Page 144: Disassembly
2) FRONT AXLE BUSH BORE DIAMETER 1.1.DISASSEMBLY 1) Dismount the front wheel drive shaft, Measure the bore diameter of the roll referring to the pertinent paragraph in chapter 2. bush in the pivot metal(F).If the measured value 2) Remove the right and left tie rods. exceeds the usable limit,replace the bush.
Page 145 Fig.6-9 Fig.6-7 Note: Slanted or forced installation of the bush should be avoided,and the bore surface of the bush should not damaged. 3) Pay particular attention to the installed direction of thrust collar,that is,with the sharply-edged face turned towards the bevel gear case. 4) When the thrust collar has been replaced or the fore-and aft play of the front axle exceeds the usable limit,correct play by screwing in the...
Page 146: Front Differential
2. FRONT DIFFERENTIAL Fig.6-10 1.Oil seal 3.Pinion bevel 8T 4.Gear bevel 35T 5.Case front Diff 6.Pinion Diff (12) 7.Thrust collar 8.Gear diff side (20) 9.Washer thrust 10.Pin spring 11.Shaft diff pinion 12. Pin spring 13.Bearing Ball(6212) 14.Snap ring 15.Snap ring( hole) 16.Shim(A) 17.Shim(B) 18.Bearing taper roller 19.collar 20.Nut(M30)
Page 147: Disassembly
2.1 DISASSEMBLY 6) Remove the bearings from the Axle housing 1) As concerns operation prior to removal of And the ring gear,and then the ring gear can the front axle,refer to the paragraph covering be separated from the Axle housing. disassembly of the center pivot 7) Remove the straight pin(4) which retains the 2) Remove both wheels...
Page 148: Reassembly
2-3.REASSEMBLY Specified thrust play 0.1-0.3 Reassembly the parts in reverse order of mm(in) (0.004-0.011 in) disassembly,following these instructions. Note: 1)Each friction surface should be coated with grease in advance. TRB and collar should be replaced as a pair. 2)The bevel pinion and the ring gear make a distinct pair after a mesh adjustment (1) Bevel pinion (8) performed at the factory.
Page 149 Fig.6-16 3) DIF CASE AND BEVEL PINION 1.shim 2.shim 3.shim 4.Parallel pin Fig.6-17 Note: Discard the removed straight pin and oil seal and install a new pin and Oil seal when reassembled,because this pin and oil 1) Each friction surface should be coated seal is apt to be damaged when removed.
Page 150: Final Case
3. FINAL CASE 3-1. Front gear case 1. Fig.6-18 1.Final drive case(A) 2.Gear bevel(9) 3.RBB(6208) 4.Pin,parallel 5.Bolt(fine) 6.Washer spring 7.Gear bevel(16) 8.RBB(6207) 11.Final drive case(B)(L) 13.Final drive case(B)(R) 14. Housing seal 15.Seal 16.RBB(6014) 17.shaft 18.Gear bevel(12) 19.RBB(6308) 20.O-ring 23.Cap 90 25.Shaft RH(296) 26.
Page 151: Disassembly
10.Bolt 3-2. Front gear case 2. 11.Nut. 12.Gear,Bevel 41 13.C-ring 14. Seal 15.Bearing,Ball/HL1 16.Bearing,Ball 17.Cover wheel shaft 18.O-ring 19.Bolt 20.Shaft,wheel 21.Washer,50X60X2 1.Case,LH Final Drive 8. 2 Case RH Final Drive (B) 3.Shaft 4.Gear Bevel 11 5.Bearing Ball 5.Bearing Ball 6.Cap 90 7.
Page 152 Note: The removed cap(90) (black plug) should be discarded and replaced when reassembled. 3.2 INSPECTION 1) Wheel shaft cover - Inspect mechanical oil seal,O-rings, Gears, cases,etc. and replace them if worn or damaged. -Measure the diameter the part which makes contact with the wheel shaft,with a micro-meter Fig.6-21 or vernier-calipers.When the measured value...
Page 153 Wheel shaft cover 3.3 REASSEMBLY 1) Every snap ring(5) should be seated securely Reassemble the parts in reverse order of in its groove. disassembly, following these instructions. 2) Be sure the numbers of Bevel gear is correct 1) Apply an adhesive (THREE BOND TB1215) (teeth numbers are 41) to the following parts.
Page 154: Steering Cylinder
- FINAL DRIVE CASE AND HOUSING - STEERING CYLINDER Fig.6-28 1) When installing the shaft,Be sure that the gears are not damaged. 2) Be sure the differences between the LH and RH shaft. Fig.6-30 Specified length 479mm 295mm 1) When installing the steering cylinder,Be sure that the rods are not damaged.
Page 155 SECTION 4. TROUBLE SHOOTING PROBLEMS AND PROBABLE CAUSES COUNTERMEASURES ● Steering wheel hard to turn 1)Too low tire inflation Inflate to specified value 2)Broken thrust bearing Replace 3)Stuck or broken ball joint of tire-rod end Grease or replace 4)Seizure or poor lubrication of axle end bush Grease or replace ●...
Page 156: Inspection
CHAPTER 7 Rear axle and brakes SECTION 1.GENERAL DESCRIPTION----------------------------------- SECTION 2. SPECIFICATIONS--------------------------------------------- SECTION 3.DISASSEMBLY,INSPECTION,AND REASSEMBLY- 1.Rear axle housing and brake system------------------------------------ 1.1. Disassembly --------------------------------------------------------------- 1.2. Inspection ------------------------------------------------------------------ 1.3. Reassembly ---------------------------------------------------------------- SECTION 4.TROUBLE SHOOTING---------------------------------------...
Page 157: Section 1.General Description
Chapter 7. Rear axle and brakes 1. GENERAL DESCRIPTION The rear axle system is of the central axle type,which contains the final reduction gears, differential gears with diff-lock,and brakes.The power from the engine is transmitted to the right and left wheel pinions through the differential gears,and reduced in the revolution to the rear wheels by the wheel gears.
Page 158: Section 2. Specifications
SECTION 2. SPECIFICATIONS MODEL T303HST/T353HST Type Helical gears Final reduction gears Reduction ratio 0.1852 (10/54) Friction Type Wet,multi-disc,Mechanically operated Plate Outer diameter Φ210 mm Thickness 4.7 mm Lining material Paper Brake system Number of plates 2 on each side Outer diameter Φ212 mm...
Page 159: Section 3.Disassembly,Inspection,And Reassembly
SECTION 3.DISASSEMBLY,INSPECTION,AND REASSEMBLY Separate the rear axle housing from the rear transmission referring to paragraph 6.(1) of SECTION 4. SEPARATION OF MAJOR BLOCKS in Chapter 2 1 REAR AXLE HOUSING AND BRAKE SYSTEM 2.Housing rear axle 3.Bearing,Ball(6307) 4.Bearing,Ball(6211) 5.Snap ring 6.Mechanical seal 7.Wheel shaft 8.Collar(56X65X239)
Page 160 1.1 Disassembly 1) Release the bolt and nut and remove them. 2) Extract the bearing(11) with a puller and remove wheel gear(10) Fig.7-4 3) Remove the snap ring (9) ,collar (8) and pull out wheel shaft (7) Fig.7-6 1.2. INSPECTION 1) Friction plates.
Page 161 2) Metal brake 4) Wheel shaft Check the pressure plate,and brake rod for Check the shaft for abnormalities like wear, abnormality.Replace defective parts.Replace the damage,etc,and replace a defective one. metal brake whose thickness exceeds the usable limit. 5) Bearings Check them for abnormalities like hitching, irregularity,etc.in rotation after being washed clean.Replace defective ones.
Page 162 Apply force only to the shaded parts -Cam brake Take care not to deform these portions 1.Cam brake 2. O-ring Fig.7-11 5) press the wheel shaft. 6) Install the wheel gear and bearing on the wheel shaft and retain them. 7) Apply adhesive (THREE BOND 1215) to the contact surfaces of the brake metal and housing and then retain the plates by tightening the nuts...
Page 163 SECTION 4. TROUBLESHOOTING Problem Causes countermeasures 1) Rear axle · Worn or damaged bearing Replace Noises · Worn gear or wheel shaft Replace 2) Brake system · Insufficient depressing of brake Depress pedals pedals positively (1)Insufficient braking force · Improper pedal free play Adjust ·...
Page 164: Disassembly
Chapter 8 Power assisted steering system SECTION 1.GENERAL DESCRIPTION------------------------------- SECTION 2. SPECIFICATIONS---------------------------------------- 2.1 Gear pump -------------------------------------------------------------- 2.2 Steering valve ------------------------------------------------------------ 2.3 Oil tank------------------------------------------------------------------- SECTION 3. FUNCTION--------------------------------------------------- 3.1 Technical Data----------------------------------------------------------- SECTION 4.DISASSEMBLY,INSPECTION,AND REASSEMBLY 4.1 Major component------------------------------------------------------- 4.2 Special tools -------------------------------------------------------------- 4.3 Disassembly -------------------------------------------------------------- 4.4 Inspection ----------------------------------------------------------------- 4.5 Reassembly --------------------------------------------------------------- 4.5 Reassembly ---------------------------------------------------------------...
Page 165: Section 1.General Description
Chapter 8. Power assisted steering system. SECTION 1. GENERAL DESCRIPTION The hydraulics of this power-assisted steering system are actuated by a specially designed steering valve system. Non Load reaction valve blocks the L,R cylinder ports in neutral condition and does not transmits the reaction load of the tire to the steering wheel in neutral.Generally the system is used for the vehicles that treat heavy equipment or low speed traveling.
Page 166: Section 2. Specifications
SECTION 2. SPECIFICATIONS 1) GEAR PUMP MODEL T303HST/T353HST Delivery (cc/rev) Maximum pressure (kgf/㎤) Rated operation speed (rpm) 500~3500 Rotation direction C.C.W as viewed from shaft 2. Power steering valve Unit(orbitrol) MODEL T303HST/T353HST Model number OSPM 80 ON Displacement (cc/rev) Rated flow (ℓ/min) 7~20 Maximum system pressure (kgf/㎤)
Page 167: Section 3. Function
SECTION 3. FUNCTION OSPM is a hydrostatic steering unit which can be used with an add-on steering column, OTPM/OTPM-T or with the steering column integrated with the unit. The steering unit consists of a rotary valve and a rotary meter. Via a steering column the steering unit is connected to the steering wheel of the vehicle.
Page 168: Technical Data
3.1 TECHNICAL DATA OSPM Max. input flow 20 l/min [5.28 US gal/min] Ambient temperature Min. –30°C [–22°F] Max. +60°C [140°F] Surface treatment Permissible temperature assuming 120°C [248°F] for 20 minutes non-activated steering unit -30 °C Oil temperature Min. [-27°F] +90 °C Max.
Page 169 SHOCK VALVES The shock valves protect the steering unit against shocks from external forces on the steering cylinder. The shock valves in the steering unit limit the max pressure drop from L to T and from R to T. The shock valves are set at 1 l/min [0.27 US gal/min].
Page 170: Section 4.Disassembly,Inspection,And Reassembly
SECTION 4. Disassembly,Inspection,And Reassembly 1. Major component of steering valve (orbitrol) Fig.8-2 1.Dust seal ring 2. Housing spool and sleeve 3.Ball 4. Ball stop 5.Shaft seal 7.Bearing 10.Ring 11. Cross pin 12.Set of springs 13.Cardan shaft 14.Spacer 15.O-ring 16. Distributor plate 17.Gear wheel set 18.O-ring 19.End cover 20.O-ring 22.Special screw 23.
Page 171: Special Tools
2.SPECIAL TOOLS F. Fork for fitting cardan shaft (OMM) A.Holding tool, code no. SJ150L9001-01 SJ 151G9000 -1 G .Ordinary hand tools. Socket spanner (5/8 in) B .Assembly tool for shaft seal ø17.5, Ratchet spanner, 1/2” code no. code no. SJ150L4011 - 01 Torque wrench: 0-70 Nm (0-7 da Nm) Allen keys: 5 &...
Page 172: Reassembly
STEP 3. STEP 9. -Cross pin(11) -Special. Screws (22, 23) Press the pin out of the spool set. Remove the screws with a 16 mm a/flats Carefully press the spool out of the sleeve. (5/8”) spanner. -Springs (12) -End cover (19) Press the neutral position springs out of the Remove end cover sideways.
Page 173 STEP 2. Note: The ring must be able to rotate unimpeded -Shaft seal (5) by the springs. With the assembly tool the shaft seal must STEP 6 into the housing. Note that the small guide piece at the front of -Cross pin (11) the tool must remain in the hole for the output Fit the cross pin in the spool set.
Page 174 STEP 8. STEP 12 -O-rings (18) -Ball (3) Place the O-rings in the grooves on each side Place the emergency steering ball in port P. of the gearwheel rim. -Ball stop (4) -Gear ring ( 17 ) Place the ball stop in port P. Place the gearwheel rim over the distributor plate so that all holes are in line with each -Ball (37)
Page 175 STEP 17. (Test) a.Lift OSPM out of the tool and prepare it for testing. The pressure relief valve can be set either on a test panel or in a system with pressure-gauge read-off. b.Insert plastic plug. STEP 18. Dust seal (1) Guide the dust seal ring down over the shaft end press into place in the housing with assembly tool.
Page 176: Section 5. Troubleshooting
SECTION 5. TROUBLESHOOTING Problems and probable causes Counter measures 1. Steering wheel is very heavy to turn 1) Poor assemble between steering column and unit. (1)Spline of column and unit are assembled -Replace column spline tightly. (2)Spool of unit is seized by spline of column -Check column assembly face and spline length (MAX 6.5㎜) (3)Poor rotation of column...
Page 177 Problems and probable causes Counter measures 3. Free play of steering wheel 1)Too low elastic of centering spring ( Remove P port pipe line and check left and right turning) -Replace spring (1)Damaged spring or poor elastic 2) Depressed control set (1) Excessive fluid and pressure -Adjust fluid level and pressure properly (2) Depressed by foreign material...
Page 178 Problems and probable causes Counter measures 8.Serious kick-back each side (1)Poor assemble the gyrotor lower the unit -Reassemble 9. Steering wheel is very heavy to begin turning (1)Oil density is too high or cool -Replace oil 10. External Oil leakage (1)column -Replace oil seal,slide ring (2)End cap gyrotor...
Page 179: Chapter 9. Hydraulic System
Chapter 9 Hydraulic system SECTION 1. GENERAL DESCRIPTION ------------------------------ SECTION 2. SPECIFICATIONS ----------------------------------------- SECTION 3. MAJOR COMPONENT OF THE HYDRAULIC SYSTEM ------------------------------------------------------- 1.Hydraulic system ------------------------------------------------------- 2.Flow-divider -------------------------------------------------------------- 3.Flow-control valve(Slow-return check valve) ---------------------- 4.Safety valve(main relief valve)---------------------------------------- 9-10 5.Gear pump --------------------------------------------------------------- 9-15 6.Filter----------------------------------------------------------------------- 9-16...
Page 180: Section 1. General Description
Chapter 9 Hydraulic system SECTION 1. GENERAL DESCRIPTION The hydraulic system is composed of a gear pump,valves,oil filter,cylinder(actuator),piping,etc.The implement lift is operated by a control valve which is actuated by the control lever through a link mechanism. ON and OFF of the PTO is controlled by a hydraulic,wet,multi-disc clutch whose circuit is opened and closed by an electromagnetic valve in the flow-divider.
Page 181: Section 2.Specifications
SECTION 2.SPECIFICATIONS T303HST/T353HST Piston and cylinder Lift (㎏f) (At lower link top end) Cylinder port leaks (cc/min.) (Under a pressure of 9800kpa(100 ㎏f/㎠) Control Valve With gear oil SAE 80W (0.610 cu in) Cracking pressure (㎏f/ ㎠) Main relief valve Relief pressure (㎏f/㎠)
Page 182: Section 3. Major Component Of The Hydraulic System
SECTION 3. MAJOR COMPONENT OF THE HYDRAULIC SYSTEM 1.HYDRAULIC SYSTEM Fig.9-2 2.O-ring(PG6) 3.Ring-back up 4.Piston 7.Rod 8. Pin spring 9.Iron wire 10.Cylinder head 11.O-ring 12. Bolt 13.Washer spring 14.Lift crank 15.Plug 16.Bolt 17.Flow con.valve 18.Dust seal 19. O-ring(P) 20.O-ring(P) 21.Knob 22.screw 23.Washer spring 24.Nut...
Page 183: Flow-Divider
2.FLOW-DIVIDER GENERAL DESCRIPTION This valve is installed to bypass working fluid of a specified pressure from the main circuit into the PTO circuit through a fixed orifice.It includes a changeover valve for engaging and disengage the PTO clutch by means of a solenoid and a sequential valve for PTO circuit's over the main circuit. (1) Flow-divider (2) PTO pressure control valve (3) Transmission case...
Page 184 -When the solenoid is switched 「「「「 ON」」」」 The fluid from the pump flows to port B through port P,the pressure-reducing valve,and the changeover valve. The pressure of the PTO clutch circuit and that of passage(2) are the same and will be set as P₂.The pressurized fluid acts on the left-hand side of the valve,passing through port ;...
Page 185 -When the solenoid is switched 「「「「 OFF」: The fluid in the PTO clutch is unloaded to the bank through port B.Consequently pressure P2 at passage(2) becomes zero,whereas the pressure at passage (1) is P1.Then the force imposed upon the left side of spool (P1)overcomes the force imposed upon the right side (P2+spring force),so that the spool is pushed rightwards to connect port P and part A.
Page 186: Flow-Control Valve(Slow-Return Check Valve)
3.FLOW-CONTROL VALVE(SLOW-RETURN CHECK VALVE) 3.1. GENERAL DESCRIPTION This valve regulates the lowering speed of the lift by controlling the unloading flow from the lift cylinder to the tank. ①Dust seal ②Snap ring ③Collar ④Body ⑤0-ring ⑥Adjust screw ⑦Back-up ring ⑧0-ring ⑨Stop ring ⑩Poppet ⑪Spring...
Page 187 3.2 OPERATIONS 2) Up position 1) DOWN position The flow port A,overcoming the force of spring(11),pushes up poppet (10) and The fluid from port B pushes up stop ring (9) choke(C)is fully opened regardless of the of poppet(10) until the ring comes into position of adjust screw(6).Thus the fluid contact with adjust screw(6),as it reaches flows to port B and the cylinder,which...
Page 188 4. RELIEF VALVE 2) PRECAUTIONS FOR DISASSEMBLY 1)GENERAL DESCRIPTION AND REASSEMBLY This valve regulates the maximum pressure in (1)Tightening torque of lock nut (9)5.0∼6.0 the whole hydraulic circuit.The regulated ㎏f·㎠(36.2∼43.4 ft.lbs) pressure can be set with the adjust screw. (2)Install seat(2)and then tap ball(3)(5/16) lightly so as to provide tight seating.
Page 189: Gear Pump
5.GEAR PUMP 1) GENERAL DESCRIPTION This pump induces fluid from one side and delivers it from the other side,by rotating two gears meshed with each other. The actual delivery is as mentioned below,considering the consequences of fluid temperature and volume efficiency in accordance with revolution speed. That is dual pump system.
Page 190 ③Remove front and rear pump. 4)DISASSEMBLY Be sure not to be damaged the o-ring or steel NOTE: ball ①Before disassembling the pump,wash the outside clean.In the course of disassembling operation,all disassembled parts should be kept aside in a clean place such as on clean paper or cloth and be handled carefully so as to prevent them from becoming dirty or damaged.
Page 191 3) REASSEMBLY ④Tightening sequence and torque of the pump ① Install the rear pump. cover tightening bolts. ▶Install the bushing seal to bushing. ▶Tightening torque: 2.5∼2.8㎏f·m ▶Install the bushing,drive gear,gear,and bushing to the housing. ▶Install the o-ring to the cover. ▶Install the cover to the housing.
Page 192 4) INSPECTION AND REPAIR (3) Bushing ① With clean working fluid,surfaces are (1)Check all disassembled parts for damage rarely scratched and should be smooth. and wash undamaged or usable parts in ② If there are many scratches on the bore clean diesel fuel or kerosene except rubber parts.Inspect all parts referring to these walls,or on parts which are in contact with...
Page 193 (4) GEAR ①With clean working fluid,surfaces are rarely scratched and should be smooth. ②If roughness can be felt by a finger nail,they are darkened,or the shaft diameter is less than 0.03 mm replace the shaft. ③Usable shaft diameter is as below Fig.9-28 gear shaft (5) Oil seal The oil seal prevents oil leaks by its inner seal lip and...
Page 194: Filter
6. FILTER Line filter Fig. 9-31 Fig. 9-30 Filter 1)GENERAL DESCRIPTION 4) REPLACEMENT The tractor is equipped with two oil filters: Check the O-rings for damage or deformation suction filter(1) and line filter(4),for better and replace defective ones.When installing the filtration.
Page 195: Section 4. Remote Hydraulic Control
SECTION 4. REMOTE HYDRAULIC CONTROL Maximum flow (ℓ/min) Maximum pressure(bar) 12 to 400 ㎟/s Viscosity range Temperature range of the fluid -20 : BC to +80:BC Environmental temperature -40: BC to +60:BC Max. level of contamination of the fluid 19116 ISO4406 Internal leakage 3㎠/min at 100 bar 40: BC and 46 ㎟/s...
Page 196: Section 5.Hydraulic System
SECTION 5. HYDRAULIC SYSTEM 1.HYDRAULIC CYLINDER 1) Hydraulic system must be washed clean,and care must be taken not to let any foreign substances. 2) The O-ring and back-up ring should be coated with grease ahead of time.Install with care so as not to damage them.
Page 197 Fig.9-34.Lift arm 9) Adjust the angle of the roll bush from horizontal is 30° 10) Apply grease to the roll bush. 11) Apply grease to the cylinder case and lift arm face Which touched with each other. 12) When assemble the lift crank on the lift shaft, mesh their splines using the alignment marks which were put there before disassembly.
Page 198: Linkage(Internal)
2. LINKAGE (INTERNAL) 1)Before installing the linkage,apply grease to relayed drive parts. 2)Drive in the roll pin into the linkage pin through the rod and lock the pin with wire. 3)Be sure not to over operate within specified spool stroke(12mm between up and down at neutral position) Fig.9-36 Linkage (internal) 9-19...
Page 199: Linkage(External)
3.LINKAGE (EXTERNAL) Fig. 9-37 Linkage(external) 9-20...
Page 200: Main Control Valve
4. MAIN CONTROL VALVE 4.1 GENERAL DESCRIPTION This valve controls the lifting and lowering operation of the hydraulic cylinder.It has especially been developed to control the working height of the implement.It consists of a feed back valve;direction control valve,flow-control unloading valve,and holding check valve. 4.2 SPECIFICATIONS Maximum operating pressure 300 Kgf.cm(4267 psi)
Page 201: Operation
4.3 DISASSEMBLY AND INSPECTION 4.4 OPERATION 1) Neutral position In the neutral position,convensater spool(711) in open (Unload), Main spool(311) and check valve(511,531) is closed and its pressure is enough to rest the force of lift arm.. Circuit diagram in the neutral position Fig.9-43 9-22...
Page 202 2) Lifting position As main spool is moved to lifting position pump pressure is increased and open the check valve(511,531). The lift arm moved to lifting position by flowing to cylinder and operate piston. Circuit diagram in the lifting position Fig.9-44...
Page 203 2) Lowering position If main spool moved to lower positions,pump is unloading and the lift arm moved to lower position by flowing to tank in the cylinder Fig.9-45 9-24...
Page 204 5. SERVICING INSTRUCTIONS. Note: The spool and stopper bolt are tightened with 1) Required tools each other with adhesive applied to their threads, -6mm set screw wrench and torque Wrench so they should not be separated unless required. -19mm spanner and torque wrench by removing the stopper bolt,the poppet and -22mm spanner and screw wrench spring can be taken out of the spool.
Page 205 Put the poppet into hole B as shown in the figure and make sure that the poppet slides smoothly.Then put the spring in and tighten the plug,on which the O-ring must be installed,to the specified torque. -unloading valve(1) and related parts. Install the spool into hole C(Fig.9-19) in the correct direction.Put the spring in and tighten the plug to the specified torque.
Page 206: Section 6. Troubleshooting
SECTION 6. TROUBLESHOOTING Problems Causes Countermeasures 1.Lift does 1) Insufficient engine speed Raise engine speed slightly not rise 2) Insufficient transmission oil Maintain oil level by replenishing with the same kind of oil 3) Air taken in through suction Tighten securely or replace broken parts. 4) Clogged suction filter Clean.
Page 207 Problems Causes Countermeasures 2.Too low 1)Above causes can also be Repair according to above instructions. rising speed of possible lift 2) Too small a spool stroke in Inspect,readjust,or replace link mechanism if necessary. control valve 3)Broken compensator spring Replace spring. (unloading valve 1) in control valve 4)Stuck poppet...
Page 208 Problems Causes Countermeasures 8.Pump noise 1) Partially clogged suction filter or Clean. suction piping. 2) Air inhaled through suction Inspect and retighten. piping and intake pipe connections for pump 3) Loosened pump cover tightening Inspect and retighten bolts. 4) Too rich oil viscosity Replace with fluid of adequate viscosity.
Page 209 Problems Causes Countermeasures 14.Independent 1) Stuck pressure-reducing valve Lap after correcting flaws with oil stone PTO clutch is too spool quick in engaging 2) Fatigued or broken pressure- Replace. reducing valve spring 3) Worn or broken sealing of PTO Replace clutch 4) Worn friction plates or driven Replace...
Page 210 Chapter 10 Electrical accessory and instruments 10-1 SECTION 1. GENERAL DESCRIPTION ----------------------------- 10-1 SECTION 2. SPECIFICATIONS --------------------------------------- 10-2 SECTION 3. BATTERY---------------------------------------------------- 10-2 1.1. Inspection -------------------------------------------------------------- 10-2 1.2. Inspection of electrolyte level---------------------------------------- 10-2 1.3. Inspection of electrolyte specific gravity-------------------------- 10-3 1.4. Battery testing chart-------------------------------------------------- 10-5 SECTION 4.
Page 211: Electrical Accessory And Instruments
All the controls,meters, and indicators are arranged around the operator’s seat for easy Maneuverability readability,and convenience. SECTION 2. SPECIFICATIONS MODEL T303HST/T353HST PART NAME Specification(w) Quantity 1.lighting Head lights...
Page 212: Section 3. Battery
Note: SECTION 3. BATTERY When the distilled water is added,charge the battery to mix it well into the electrolyte before 1.INSPECTION measuring the specific gravity. 1.1 INSPECTION OF ELECTROLYTE LEVEL a.Temperature correction of the hydrometer As the battery repeats charging and reading discharging during operation.The water The specific gravity of the battery...
Page 213: Battery Testing Chart
1.4 BATTERY TESTING CHARTS Step 1. VISUAL INSPECTION Check for obvious damage such as cracked or broken case that shows loss of electrolyte,thermal damage,etc. Obvious damage No obvious damage Replace battery Check electrolyte level Electrolyte level is below top of Electrolyte level is above top of plates in one or more cells plates in all cells...
Page 214 Step 3 Load test 1.Connect voltmeter and ampere load equal to ½ the cold cranking amperes(18℃) rating of the battery for 15 seconds. 2. Observe voltage at 15 seconds with load on.Disconnect load 3.Place thermometer in one cell to take temperature of electrolyte. 4.Refer to voltage table Voltage below table value Voltage equal to or above table...
Page 215: Section 4. Meters And Switches
SECTION 4. METERS AND SWITCHES 1.METERS The generated pulses are converted into voltage 1.1 Removal output through a converter.Then the voltage is divided into three different phase coils through a a. Disconnect the cable from the negative post. IC circuit.The tachometer pointer is swung by b.
Page 216: Thermometer
b.Inspection -Fuel meter Note: Connect the fuel gauge to form a circuit with the 1) Figures in parentheses are reference value resisters as shown Fig.10-6 and check to see if 2) Inspect each position in order F to E the gauge pointer swings to each position: F.1/2 3) Read values in three minutes.
Page 217: Combination Switch
(2) Inspection a.The main switch circuit,switching positions, and terminals are as shown in the figures. Check the continuity across respective terminals referring to the switch circuit diagram. Replace a defective switch as an assembly Fig.10-12 (3) Release the ring nut with a conventional screw drive(-) and remove the combination switch.
Page 218: Stop Light Switch
-Lighting 4. STOP LIGHT SWITCH Color code ● ● ● ● ● ● Fig.10-15 Stop light switch :Terminals : Switching positions Capacity 15 A (DC12V) -Flasher 2 ±0.8mm Stroke to ON Color Total stroke code (Green) (White/ (Green/ 5.RELAY UNIT Green) Black) ●...
Page 219 7. CONTROLLER Each fuse is connected as follows Fig.10-20 Fig.10-18 Capacity DC12V Light / Horn Operating range DC10~16V Panel Operating temperature -15~80ºC Turn Signal Lamp Working Light 7.5A 1.Function Hazard a. Engine stop Coupler When below condition is performed,Engine Controller Glow Timer will be stopped within 10±3 sec.( 1 PTO, Cruise, PTO, Cruise,...
Page 220 2. CIRCUIT DIAGRAM Fig.10-21 controller Fig.10-22 connector 1.Battery(+12V) 11.GND 2.Battery(+12V) 12.HST S/W 3.Hey(+12V) 13.Seat S/W 4.Generator charger signal 14.N.C 5.Brake S/W 15.PTO S/W 6.Parking brake S/W 16.N.C 7.Cruise S/W 17.Cruise lamp 8.Check valve 18.Cruise magnetic 9.Starter S/W 19.Starter relay 10.Engine stop solenoid 20.Engine stop solenoid 10-10...
Page 221: Trailer Socket(7P)
8.Trailer socket A hella’s 7-pin trailer socket is equipped as a standard equipment.Lamp on a trailer can be operated through the socket. A type B type Fig.10-23 Socket No. Description Color Specification Wire Housing A type B type Earth AV 1.25 Small light(Tail light) AV 1.25 Turn signal (LH)
Page 222: Section 5. Earthing Point
SECTION 5. EARTHING POINT Fig.10-24 2) Contact surfaces of the Hood frame and 1) Fuel tank guard (RH) bracket where they tightened together Earthed at tapped hole in the lower the working lamp Fig.10-25 10-12 Fig.10-26 Hood frame...
Page 223 3) Right surface of the frame comp.Where the battery cable is to be installed. Fig.10-27 Battery cable Fig.10-27 Battery cable 10-13...
Page 224: Section 6. Wiring Diagram
SECTION 6. WIRING DIAGRAM 10-14...
Page 225: Section 7. Troubleshooting
SECTION 7. TROUBLESHOOTING Important: Whenever effecting a repair the reason for the cause of the problem must be investigated and corrected to avoid repeating failure. The following table lists problems and their possible causes with the recommended remedial action 1. LIGHTING SYSTEM Problems Causes Countermeasures...
Page 226 Problems Causes Countermeasures Individual Burnt out bulb Check and renew turn signal Corroded or loose bulb contacts Inspect,clean,and renew light does not illuminate Poor ground connection or damage Inspect,clean,and tighten connections or wiring renew wiring Turn signal Faulty bulb Check and renew pilot light is Defective flasher unit Check and renew...
Page 227 Problems Causes Countermeasures Inoperative Burnt out fuse Inspect and renew.Check circuit before re- horn connecting power Loose or broken wires of Inspect circuit,tighten connections,or renew connections wiring Defective horn switch Check and renew Defective horn Check and renew Cruise does Burnt out fuse Inspect and renew.Check circuit before re- not operate...
Page 228 4. STARTING SYSTEM Problems Causes Countermeasures Starter motor Discharged battery Check battery and charge or renew does not spin Defective stop light switch Check and renew Defective key switch Check and renew Defective starter motor connections Check,clean and tighten connections or loose battery connections Faulty starter motor Inspect,repair,or renew...
Page 229 Problems Causes Countermeasures Intermittent Alternator drive belt is slipping Check and adjust belt tension or renew or low Loose connection or broken cable in Inspect system,tighten connections and alternator charge system repair or renew faulty wiring output Defective alternator Check and repair or renew Warning light Faulty external charging circuit Inspect system,clean and tighten...
Page 230: Chapter 11. Service Standard And Other Information
CHAPTER 11. Service standards and other information 11-1 SECTION 1. SERVICE STANDARDS ------------------- 11-1 1.Engine accessories -------------------------------------- 11-2 2.Clutch damper-------------------------------------------------- 11-2 3.Transmission -------------------------------------------- 11-3 4.Front axle ------------------------------------------------- 11-4 5.Rear Axle--------------------------------------------------------- 11-4 6.Power steering system ---------------------------------------- 11-4 7.Hydraulic system ----------------------------------------------- 11-7 8.Electrical equipment-------------------------------------------- SECTION 2.
Page 231: Service Standards And Other Information
CHAPTER 11. Service standards and other information SECTION 1. SERVICE STANDARDS. Part names and Nominal Standard value Usable limits Service instructions inspection items dimensions for reassembly and remarks 1.ENGINE ACCESSORIES(CHAPTER 3) 1) RADIATOR Coolant capacity 2.5 ℓ Radiator alone 7ℓ Whole cooling system 0.9 ±0.15㎏f·㎠...
Page 232: Clutch Damper
Part names and Nominal Standard value Usable limits Service instructions inspection items dimensions for reassembly and remarks 2.CLUTCH DAMPER Spline No.of teeth Large Ø22.35 diameter Small Ø19.9 diameter 3. TRANSMISSION (CHAPTER 5) 1) FRONT AND SPACER TRANSMISSIONS TRANSMISSION OIL CAPACITY 35ℓ(9.25 US gal) SHIFTER DISENGAGING LOAD 4 - 6 ㎏f...
Page 233 Part names and Nominal Standard value Usable limits Service instructions inspection items dimensions for reassembly and remarks (2) DIFFERENTIAL 0.1 ∼ 0.2 ㎜ 0.5 ㎜ Backlash between Pinion thrust collar or dif-pinion and dif- gear side gear 4.FRONT AXLE (CHAPTER 6) 1) Front drive axle (4WD) Front : 2.2 ㎏f/㎠...
Page 234: Rear Axle
Part names and Nominal Standard value Usable limits Service instructions inspection items dimensions for reassembly and remarks 5.REAR AXLE (CHAPTER 7) 1) DISK BRAKE 4.7 ± 0.1 ㎜ 4.2 ㎜ FRICTION PLATE THICKNESS (WEAR AND CARBONIZER ) 2)SEPARATE PLATE 2.5 ± 0.09 ㎜ 2.5 ㎜...
Page 235 Usable limits Service instructions inspection items dimensions for reassembly and remarks 2) Dynamic lift 2000 ㎏f·㎠ T303HST/T353HST 3) Cylinder case bush 55 ×60 ×50 Ø 55 ㎜ Ø 55.2 ㎜ Wear limit: 0.2 ㎜ Left side 60 ×65 ×50 Ø 60 ㎜...
Page 236 50 ± 5℃ 0.01 ㎜ Clearance between main spool and casing 8) MAIN RELIEF VALVE 160+5 ㎏f/㎠ T303HST/T353HST 9) MAIN GEAR PUMP T303HST/T353HST 21.5 ℓ/min Efficiency of 92 % at 2600 rpm 10) SUCTION FILTER Rated flow 35 ℓ/min...
Page 237: Electrical Equipment
8.ELECTRICAL EQUIPMENT 1)BATTERY (1)BATTERY TERMINAL POST Terminal voltage 12 V 10.8 V Charge or replace Corrosion Repair or replace (2) BATTERY CELLS Damage Replace battery (3) ELECTROLITE Cloudy fluid Replace battery Specific gravity 1.24 - 1.26 Correct Level As specified on Replace with distilled case water.
Page 238 (3) Turn signal switch Replace a defective ●Turn signal switch switch assembly. (4) Horn switch Replace a defective ●Horn switch switch assembly. (6) PTO SWITCH Continuity across Switched on when lever is moved by about 3 mm Replace a defective each terminal (0.12 in) across R and LR switch assembly.
Page 239 (9) HAZARD WARNING SWITCH Replace a defective ○ ○ ○ ○ switch assembly. Continuity across each terminal ○ ○ ○ ○ ○ ○ ○ ○ 10 9 11-9...
Page 240 SECTION 2.TIGHTENING AND STARTING TORQUE SPECIFIED FOR MAJOR PARTS T303HST/T353HST TIGHTENING PARTS BOLT AND NUT TIGHTENING TORQUE (HARDNESS) (㎏f·m) 1)Front axle housing (4WD type) ①Axle bracket ∼ Engine tightening bolts M 16 (7T) 16.0 ∼ 18.0 ②Front pivot metal(support)tightening bolts M 12 (7T) 9.0 ∼...
Page 241: Section 3. Conversion Tables
SECTION 3. CONVERSION TABLES M illimeters to inches M illimeters to inches M illimeters to inches M illimeters to inches Inches to millimeters Inches to millimeters Inches to millimeters Inches to millimeters 0.0394 1.0236 2.0079 2.9921 1/64 0.3969 25/64 9.9219 13/16 20.6375 0.0787...
Page 242 L ength L ength L ength L ength Fe et to M e te rs Fe et to M e te rs Fe et to M e te rs Fe et to M e te rs 0.0000 0.3050 0.6100 0.9150 1.2200 1.5250 1.8300...
Page 243 Are a Are a Are a Are a S quare inc h e s to s qu are ce ntime te rs S quare inc h e s to s qu are ce ntime te rs S quare inc h e s to s qu are ce ntime te rs S quare inc h e s to s qu are ce ntime te rs 0.000 6.462...
Page 244 V ol u me V ol u me Gal l ons ( U.S ) to L i te rs Gal l ons ( U.S ) to L i te rs V ol u me V ol u me Gal l ons ( U.S ) to L i te rs Gal l ons ( U.S ) to L i te rs US gal US gal...
Page 245 M AS S M AS S Pou nds to Ki l ograms Pou nds to Ki l ograms M AS S M AS S Pou nds to Ki l ograms Pou nds to Ki l ograms 0.000 0.454 0.907 1.361 1.814 2.268 2.722...
Page 246 P re s s u r e P re s s u r e Pou nds pe r s qu are i nc h e s to Ki l ograms pe r s qu are c e nti me te rs Pou nds pe r s qu are i nc h e s to Ki l ograms pe r s qu are c e nti me te rs P re s s u r e P re s s u r e...
Page 247 Torqu e Torqu e Foot pou nds to Ki l ogram me te rs Foot pou nds to Ki l ogram me te rs Torqu e Torqu e Foot pou nds to Ki l ogram me te rs Foot pou nds to Ki l ogram me te rs ft lbs Kg-m Kg-m...
Page 248 Temperature Fahrenheit to Centigrade Centigrade to Fahrenheit ˚F ˚C ˚F ˚C ˚C ˚F ˚C ˚F -28.9 35.0 -22.0 96.8 -26.1 37.8 -18.4 100.4 -23.3 40.6 -14.8 104.0 -20.6 43.3 -11.2 107.6 -17.8 46.1 -7.6 111.2 -17.2 48.9 -4.0 114.8 -16.7 51.7 -0.4 118.4...
Page 249 T303HST/T353HST Workshop manual FOR TRACTORS CODE NO. Printed on April. 2008 EDITION Edited by overseas service team...

This manual is also suitable for:

T353hst

TYM T303HST Workshop Manual

T303Hst/T353Hst

Chapter 2 Disassembly and Reassembly of Major Components

Chapter 3 Engine Accessories

Chapter 4 Hst System

Chapter 5 Transmission

Chapter 6 Front Axle

Inspection/Reassembly

Disassembly/Inspection

Chapter 9. Hydraulic System

Chapter 10 Electrical Accessory and Instruments

Quick Links

Chapters

Troubleshooting

Need help?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for TYM T303HST

Summary of Contents for TYM T303HST

This manual is also suitable for:

Table of Contents