Twin Disc MG-5170DC Service Manual

Marine transmission

Table of Contents

Quick Links

TWIN DISC

INCORPORA

INCORPORATED

INCORPORA

Ser

vice

Ser vice

vice

Ser

vice

Manual

TED

Marine

T T T T T r r r r r ansmission

ansmission

Components:

MG-5170DC

Document Number: 1020667

Table of Contents

Need help?

Do you have a question about the MG-5170DC and is the answer not in the manual?

Questions and answers

Summary of Contents for Twin Disc MG-5170DC

Page 1 TWIN DISC TWIN DISC TWIN DISC TWIN DISC TWIN DISC INCORPORA INCORPORATED INCORPORA INCORPORA INCORPORA vice vice Ser vice vice vice Manual Manual Manual Manual Manual Marine Marine Marine Marine Marine T T T T T r r r r r ansmission...
Page 2 NOTICE Twin Disc, Incorporated makes no warranty or guaranty of any kind, expressed, implied or otherwise, with regard to the information contained within this manual. Twin Disc, Incorporated has developed this manual through research and testing of the information contained therein. Twin Disc, Incorporated assumes...
Page 3 Document Number 1020667 July, 2002 Marine Transmission Service Manual...
Page 5 (24) months from the date of shipment by Twin Disc, Incorporated to original customer, but not to exceed twelve (12) months of service, whichever occurs first. This is the...
Page 6 TWIN DISC, INCORPORATED FLAT RATE HOUR ALLOWANCE (Hourly Labor Rate Must be Acceptable to Twin Disc, Incorporated.) COMMERCIAL MARINE TRANSMISSIONS - ALL RATIOS: MODEL SERIES R&R UNIT REBUILD CLUTCH REPAIR (BOTH PACKS) MG 502, MG 5010, MG5011, MG5005A MG5015A 10.0 MG 506, MG5061, MG 5050, MG5055A 10.0...
Page 7: Table Of Contents
Table of Contents Twin Disc, Incorporated Table of Contents Introduction ............11 General Information ................11 Safety and General Precautions ............ 11 Preventative Maintenance ..............13 Towing....................13 Ordering Parts and Obtaining Services ......... 14 Source of Service Information............15 Warranty ....................
Page 8 Table of Contents Twin Disc, Incorporated Troubleshooting ..........67 Troubleshooting Chart ..............67 Disassembly ............71 Prepare Transmission for Disassembly ........72 Remove Transmission External Components and Sub-Assemblies ................73 Remove Clutch Assemblies ............. 76 Remove Primary and Secondary Clutch Shaft Assemblies ..79 Remove Output Flange and Oil Pan ..........
Page 9 Table of Contents Twin Disc, Incorporated Installation............167 Prior to Installation................167 Alignment (also reference SAE J-1033 and J-617) ..... 168 Installation ..................172 Centaflex-R Assembly Instructions on Flange Mounted Gears ....................179 Special Tools ............. 185 List of Special Tools ................. 185 Bearing Driver T-18050-11 ...............
Page 10 Table of Contents Twin Disc, Incorporated Illustrations ............209 List of Illustrations ................209 Clutch Group ..................210 Suction Strainer ................212 Oil Filter ....................213 Transmission Rear View ..............214 Transmission Section View............. 216 Torsional Input Coupling ..............218 Manual Control Valve ...............
Page 11: Introduction
Safety and General Precautions General All personnel servicing this equipment should employ safe operating practices. Twin Disc, Inc. will not be responsible for personal injury resulting from careless use of hand tools, lifting equipment, power tools, or unaccepted maintenance/working practices.
Page 12 Proper installation, maintenance, and operation procedures must be followed due to the possible danger to person(s) or property from accidents that may result from the use of machinery. Twin Disc, Inc. will not be responsible for personal injury resulting from careless maintenance/working practices.
Page 13: Preventative Maintenance
Lock the propeller shaft to prevent rotation. Add an electric-driven auxiliary oil pump into the lubrication circuit. Refer to the hydraulic system prints for more details on auxiliary pump specifications for the applicable transmission, or contact your Twin Disc Authorized Distributor. Marine Transmission Service Manual #1020667...
Page 14: Ordering Parts And Obtaining Services
Twin Disc. All returned parts, new or old, emanating from any of the above stated changes will not be accepted for credit. Furthermore, any equipment that has been subjected to such changes will not be covered by a Twin Disc warranty.
Page 15: Source Of Service Information
Source of Service Information For the latest service information on Twin Disc products, contact any Twin Disc distributor or service dealer. This can be done on the Twin Disc corporate web site found at [http://www.twindisc.com]. Provide your model number, serial number and bill of material number to obtain information on your unit.
Page 16: Warranty
Equipment for which this manual was written has a limited warranty. For details of the warranty, refer to the warranty statement at the front of this manual. For details of the warranty, contact any Twin Disc Authorized Distributor, service dealer, or the Warranty Administration Department, Twin Disc, Inc., Racine, Wisconsin, U.S.A.
Page 17: Description And Specifications
The nameplate identifies the model, bill of material (BOM) and the serial number of the unit. These numbers are necessary to identify the correct parts for your transmission. Figure 1. Nameplate for MG-5170DC Marine Transmission Marine Transmission Service Manual #1020667...
Page 18: Power Ratings
Description and Specifications Twin Disc, Incorporated Power Ratings The MG-5170DC transmission can be operated through either the primary shaft or secondary shaft at its full rated horsepower when driven by a standard right hand rotation engine (counterclockwise flywheel rotation when viewing rear of engine).
Page 19: Construction Features
Construction Features Housings The MG-5170DC transmission has a one-piece main housing. Front housing sizes in SAE No. 0 and SAE No. 1 sizes are available. A top cover, oil pan, bearing carrier, and manifold (sealed with gaskets) complete the housing enclosure.
Page 20: Lubrication Features
A spin-on oil filter is located between the heat exchanger outlet and the selector valve in the hydraulic circuit. The replacement element is Twin Disc part number XB3614A. This should be replaced at 1000 hour or six month intervals, whichever comes first.
Page 21 Absorb shock and reduce noise Minimize gear “rattle” Several couplings are available from Twin Disc, and are selected based on the customer supplied engine information. Final coupling selection must be confirmed by the packager based on the torque/rpm ratings and the results of the system torsional vibration analysis (TVA), and on engine rotation.
Page 22 Description and Specifications Twin Disc, Incorporated Heat Exchanger The heat exchanger is designed to maintain the oil in the hydraulic system of the marine transmission at the proper temperature by passing raw or fresh water through the heat exchanger. The heat exchanger should be installed in a location convenient to both coolant and marine transmission oil.
Page 23: Specifications
Description and Specifications Twin Disc, Incorporated Specifications Maximum operating speed: 2500 rpm Maximum oil sump temperature: 93° C (200° F) Oil type and viscosity: See data plate below Oil capacity: 28 liters (7.5 gal) plus hoses and heat exchanger Oil Pump: 53.4 liters per minute (14.1GPM) at 1800 RPM Approximate Dry weight: 849 kg (1870) lbs.
Page 24 Description and Specifications Twin Disc, Incorporated Table 1. MG-5170DC Oil Pressure Specifications Oil pressure Limits - 1725 kPa (250 psi) rating (235psi minimum pressure when cruising) Oil pressure Limits - 1725 kPa (250 psi) rating (235psi minimum pressure when cruising)
Page 25: Optional Equipment
Description and Specifications Twin Disc, Incorporated Optional Equipment The following optional equipment for use with the model MG-5170DC is available through the nearest authorized Twin Disc distributor. Optional Trailing Pump A 115 vac electric powered trailing pump system is available. It is identified as part number 1016473.
Page 26 Description and Specifications Twin Disc, Incorporated Companion Flange Assembly The 1017494 companion flange assembly consists of the companion flange as well as the 8 bolts and nuts to secure it to the marine transmission’s output flange. Trolling Valve Several trolling valve kits are available for use with this transmission. The XA7371 control valve uses the XA7373Q trolling valve, which is mechanically actuated.
Page 27 Description and Specifications Twin Disc, Incorporated Table 2. Gear Advance Transmission Primary and Secondary Transfer Gear Advance Minimum Maximum 1.96mm (.077 in) 2.97mm (.117 in) Transmission Output Gear Advance Minimum Maximum 3.35mm (.132 in) 4.42mm (.174 in) Table 3. Bearing End Play...
Page 30: Torque Values For Fasteners
Description and Specifications Twin Disc, Incorporated Torque Values for Fasteners Note: All threads and bearing face to be lubricated with light oil film prior to assembly. Table 4. U.S. Standard Fine and Coarse Thread Capscrews, Bolts, and Nuts SAE Grade 5...
Page 31 Description and Specifications Twin Disc, Incorporated Table 5. Metric Coarse Thread Capscrews, Bolts, and Nuts Property Class 8.8 Property Class 8.8 Property Class 8.8 Property Class 10.9 Property Class 10.9 Property Class 10.9 Property Class 12.9 Property Class 12.9 Property Class 12.9...
Page 32 Description and Specifications Twin Disc, Incorporated Table 7. Straight Threaded Tube Fittings, Hose Fittings, and O-ring Plugs Nominal Nominal Nominal Nominal lb-ft lb-ft lb-ft lb-ft Thread Thread T hread T hread + or - 5 % + or - 5 %...
Page 33: Operation
Operation Twin Disc, Incorporated Operation General The control valve obtains primary, neutral and secondary positions. When these positions are selected, the control valve directs high-pressure oil through internal passages to operate the clutches. The pressure-rate control piston within the control valve assembly provides a rapid, smooth, oil pressure increase in the hydraulic system during clutch engagement.
Page 34: Hydraulic System With Manual Control Valve
Operation Twin Disc, Incorporated Hydraulic System with Manual Control Valve The oil pump draws oil through the strainer from the oil sump and discharges it through the oil filter. Filtered oil enters the control valve through the inlet port. The incoming oil forces the pressure regulator piston against the springs to open the path to the lubrication circuit.
Page 36: Manual Control Valve
Operation Twin Disc, Incorporated Manual Control Valve — Neutral Refer to Figures 7 and 8. Oil enters the control valve body through passage A and fills chamber B. The oil causes the pressure regulating piston to partially compress the piston outer and inner springs against the pressure-rate control piston.
Page 37 Operation Twin Disc, Incorporated Figure 7. Manual Control Valve — Neutral — Sectional View Figure 8. Manual Control Valve — Neutral — Cutaway View Marine Transmission Service Manual #1020667...
Page 38 Operation Twin Disc, Incorporated Manual Control Valve — Primary When a shift to the primary position is desired, the control valve lever is moved. The shift causes the control valve stem to rotate and assume the position indicated in Figures 9 and 10.
Page 39 Operation Twin Disc, Incorporated Figure 9. Control Valve — Primary — Sectional View Figure 10. Control Valve — Primary — Cutaway View Marine Transmission Service Manual #1020667...
Page 40 Operation Twin Disc, Incorporated Manual Control Valve — Secondary When a shift to the secondary position is desired, the control valve lever is moved. The shift causes the control valve stem to rotate and assume the position indicated in Figures 11 and 12.
Page 41 Operation Twin Disc, Incorporated Figure 11. Control Valve — Secondary — Sectional View Figure 12. Control Valve — Secondary — Cutaway View Marine Transmission Service Manual #1020667...
Page 42: Hydraulic System With Optional Electric Control Valve
Operation Twin Disc, Incorporated Hydraulic System with Optional Electric Control Valve The oil pump draws oil through the strainer from the oil sump and discharges it through the oil filter. Filtered oil enters the control valve through the inlet port.
Page 43 Operation Twin Disc, Incorporated The pressure in the rate-of-rise chamber is controlled by a ball that is spring loaded against the orifice plate. The passage behind the ball and spring is connected to the sump (atmosphere) in Neutral and to main pressure when either clutch is engaged.
Page 44 Operation Twin Disc, Incorporated Control Valve Assembly in Neutral Some of the main pressure oil from the oil inlet chamber flows through a passage to the orifice in the orifice plate. The small flow of oil through this orifice fills and begins to pressurize the rate-of-rise chamber.
Page 45 Operation Twin Disc, Incorporated Control Valve Assembly in Primary or Secondary Pressurized oil is directed to one of the transmission’s clutches to engage it. The pressurized oil in the clutch port of the engaged clutch acts on the shuttle ball, sealing off the passage to the opposite clutch. The pressurized oil also forces the ball of the ball and spring regulator against its seat on the orifice plate, stopping the flow of oil from the rate-of-rise chamber to sump.
Page 46 Operation Twin Disc, Incorporated Electric Operation The transmission normally operates with the control valve in the electric mode. Two spools, each controlled by a solenoid operated pilot valve, control clutch engagement. When a solenoid is energized, it opens the pilot valve and allows main pressure oil to flow to the end of the spool.
Page 47 Operation Twin Disc, Incorporated Main pressure oil flows from the spools above to the clutch passages of the transmission below via connecting slots in the manual override stem. These connecting slots are aligned with passages in the valve body when the valve is in the electric mode.
Page 48 Operation Twin Disc, Incorporated Hydraulic Lock Feature (some models) Some control valve models have a hydraulic lock feature, and are identifiable by a third solenoid operated pilot valve. This feature keeps the engaged clutch pressurized as long as the engine remains running, should electrical power fail or malfunction occur while the clutch is engaged.
Page 49 Operation Twin Disc, Incorporated The hydraulic lock is disabled when either the engine is stopped, or the neutral solenoid is energized. When the neutral solenoid is energized, it sends pressurized oil to the dowel pins at the return spring end of each spool.
Page 50 Operation Twin Disc, Incorporated Manual Override Operation The control valve has a manual override feature, which is a lever operated selector. When the manual override lever is rotated counterclockwise and pulled outwards, the upper portion of the valve is disabled because the connecting slots in the manual override stem are no longer aligned with the oil passages in the valve body.
Page 51 Operation Twin Disc, Incorporated Figure 21. Hydraulic Schematic (electric control valve) Marine Transmission Service Manual #1020667...
Page 52: Trolling Valve (Optional)
Operation Twin Disc, Incorporated Trolling Valve (Optional) The trolling valve is used to reduce and control propeller speed below that normally attained by operating the engine at low idle. Actuating the trolling function reduces clutch apply pressure to reduce the propeller speed.
Page 53 Operation Twin Disc, Incorporated Mechanical Trolling Valve This trolling valve is a variable orifice that controls the pressure in the rate-of- rise chamber. The pressure in the rate-of-rise chamber determines the rate- of-rise piston position, which ultimately controls the main and clutch pressures for the transmission.
Page 54 Operation Twin Disc, Incorporated 1017554 Electric Trolling Valve This trolling valve is a variable orifice that controls the pressure in the rate-of- rise chamber. The pressure in the rate-of-rise chamber determines the rate-of- rise piston position, which ultimately controls the main and clutch pressures for the transmission.
Page 55: Power Take-Off (Optional)
Operation Twin Disc, Incorporated Power Take-off (Optional) There is a separate manual (part number 1020075) which describes the operation, installation, troubleshooting, and service of the optional Power Take- off (PTO) for this marine transmission. Live Power Take-off The live PTO drives accessories using engine horsepower. Since the live PTO connects the accessory to the primary shaft of the transmission via a direct coupling, the accessory is driven when the engine is running.
Page 56: Trailing Pump (Optional)
Operation Twin Disc, Incorporated Trailing Pump (Optional) The trailing pump is used to supply oil flow to the transmission lubrication circuit when the transmission is in a backdriving condition. Backdriving (sometimes referred to “windmilling”) occurs when the engine is shut down and the transmission output shaft is being driven by water flow across the propeller.
Page 57: Power Flow
Operation Twin Disc, Incorporated Power Flow Input power to the transmission is through a torsional coupling mounted on the engine flywheel. The coupling is splined to the forward end of the primary (forward clutch) shaft causing the primary shaft to rotate in engine direction during engine operation.
Page 58 Operation Twin Disc, Incorporated Neutral When in neutral the primary and secondary shafts, transfer gears and clutch friction plates rotate at engine speed. Figure 23. MG-5170DC Power Flow in Neutral Marine Transmission Service Manual #1020667...
Page 59 The secondary input pinion will be backdriven (engine direction) when the unit is in the primary position. Figure 24. MG-5170DC Power Flow with Primary Clutch Engaged Marine Transmission Service Manual #1020667...
Page 60 The primary input pinion will be backdriven (anti-engine direction) when the unit is in the secondary position. Figure 25. MG-5170DC Power Flow with Secondary Clutch Engaged Marine Transmission Service Manual #1020667...
Page 61: Preventative Maintenance
Preventative Maintenance Twin Disc, Incorporated Preventative Maintenance In-boat Maintenance and Repair Certain transmission maintenance/repair procedures can be accomplished in the boat provided sufficient space exists to work. These procedures are: Removing and installing the oil pump. Changing the filter. Removing, cleaning and installing the suction strainer.
Page 62: General Maintenance
Preventative Maintenance Twin Disc, Incorporated General Maintenance Lubrication Grease the oil seals on the output end of the output shaft through the grease fitting with water pump (lithium soap-based NLGI No. 2) grease. Apply grease every 100 hours or when the boat is docked.
Page 63 Preventative Maintenance Twin Disc, Incorporated Draining Drain the transmission by removing the O-ring plug at the rear side at the bottom. Oil Suction Strainer Remove and clean the pump suction strainer at every oil change or sooner if necessary. The suction strainer is located in the manifold below the pump.
Page 64 Preventative Maintenance Twin Disc, Incorporated Torsional Coupling Do not obstruct the flywheel housing vents preventing the free flow of air for cooling the coupling. The ambient temperature of the air around the coupling ° ° ° ° should be between -6...
Page 65 Preventative Maintenance Twin Disc, Incorporated Inspect the hub, looking for the following: Damaged or worn splines. Cracked parts. Oil seal surface for wear or damage. Replace any defective parts including defective fasteners that are found. Marine Transmission Service Manual #1020667...
Page 66 Twin Disc, Incorporated Heat Exchanger Check Heat exchangers furnished by Twin Disc to be used for salt water applications have zinc rods installed at the inlet and outlet heads. These rods must be checked every 90 days. If over 50% of the rod is disintegrated, it should be replaced to provide effective protection.
Page 67: Troubleshooting
Troubleshooting Twin Disc, Incorporated Troubleshooting Troubleshooting Chart The following chart is intended as a guide for determining the cause of problems that could be encountered and the corrective actions for those difficulties. The transmission is one part of a complete power package. Problems in the input power system or the output power delivery components can cause problems to develop in the transmission.
Page 68 Troubleshooting Twin Disc, Incorporated Table 8. Troubleshooting Chart Symptom Symptom Symptom Cau se Cau se Cau se Remedy Remedy Remedy Partially clogged oil Partially clogged oil Partially clogged oil Remove and clean oil Remove and clean oil Remove and clean oil...
Page 69 Troubleshooting Twin Disc, Incorporated Table. 8. Troubleshooting Chart (continued) Symptom Symptom Cau se Cau se Remedy Remedy Remove and clean Remove and clean High main oil pressure. High main oil pressure. Regulating valve stuck. Regulating valve stuck. regulating valve. regulating valve.
Page 70 Troubleshooting Twin Disc, Incorporated Table. 8. Troubleshooting Chart (continued) Symptom Symptom Cau se Cau se Remedy Remedy Remove clutch plates. Remove clutch plates. No neutral. No neutral. Clutch plates warped. Clutch plates warped. O verhaul unit. O verhaul unit. Control valve incorrectly...
Page 71: Disassembly
Disassembly Twin Disc, Incorporated Disassembly The following procedure is for complete disassembly of the unit. Prior to this procedure, the transmission should be removed from the boat. Qualified personnel should do the work in a fully equipped facility. Marine Transmission Service Manual #1020667...
Page 72: Prepare Transmission For Disassembly
Disassembly Twin Disc, Incorporated Prepare Transmission for Disassembly Note: During service of this unit, all O-rings, gaskets and seals must be replaced. It is good practice to keep the old O- rings, gaskets and seals with the appropriate components being disassembled for future reference during the inspection and assembly process (to make sure you don’t...
Page 73: Remove Transmission External Components And Sub-Assemblies
Disassembly Twin Disc, Incorporated Remove Transmission External Components and Sub-Assemblies Remove coupling from spline on primary shaft (if not previously removed). Remove front housing from main housing. Support the unit on an assembly stand or blocks with the output side facing up.
Page 74 Disassembly Twin Disc, Incorporated Remove the control valve and gasket. Set it aside for later disassembly. Remove breather and oil filler screen from top cover plate. Figure 28. Removing Breather and Screen Remove top cover plate and gasket. Remove oil pump and gasket.
Page 75 Disassembly Twin Disc, Incorporated Remove suction strainer cover (hex head O-ring plug). Remove spring and suction strainer. Figure 30. Removing Suction Strainer Marine Transmission Service Manual #1020667...
Page 76: Remove Clutch Assemblies
Disassembly Twin Disc, Incorporated Remove Clutch Assemblies Remove primary shaft end cover plate and O-ring. Figure 31. Removing Primary Shaft Cover (left) and O-ring (right) Remove manifold attaching screws. Install two of the removed screws into the pusher screw holes near the dowel pins. Tighten the screws alternately and evenly to push the manifold off of the bearing carrier and dowel pins.
Page 77 Disassembly Twin Disc, Incorporated Remove the bearing spacers and shims from the bearing bores of the bearing carrier. Mark the shims and spacers for location identification. Figure 33. Removing Spacers and Shims Remove the lubrication tube from the bearing carrier.
Page 78 Disassembly Twin Disc, Incorporated Install two of the removed screws into the threaded pusher screw holes of the bearing carrier (near the dowel pins). Tighten the screws alternately and evenly to push the bearing carrier off of the housing and dowel pins.
Page 79: Remove Primary And Secondary Clutch Shaft Assemblies
Disassembly Twin Disc, Incorporated Remove Primary and Secondary Clutch Shaft Assemblies Lift out primary shaft. (Disassembly of the primary and secondary shafts are covered later in this section.) Use caution with the front pinion bearing cones. They are loose on the pinion diameter, and should remain in the housing.
Page 80 Disassembly Twin Disc, Incorporated Remove front pinion tapered roller bearing cones that were pulled off by output gear as primary and secondary shafts were removed. Note: Tapered roller bearing cups of front bearings on the primary and secondary shafts are an interference fit in the housing.
Page 81: Remove Output Flange And Oil Pan
Disassembly Twin Disc, Incorporated Remove Output Flange and Oil Pan Remove the output flange retaining capscrews. Remove the retaining washer, shims and O-ring. Figure 40. Removing Washer and Shims (left) and O-ring (right) Use hydraulic ram to pull the output flange from the output shaft.
Page 82 Disassembly Twin Disc, Incorporated Remove the oil gauge tube assembly. Figure 42. Removing Oil Gauge Tube Assembly Remove the oil pan attaching screws. Remove the oil pan and gasket. Figure 43. Removing Oil Pan Marine Transmission Service Manual #1020667...
Page 83 Disassembly Twin Disc, Incorporated Remove the gear pan from the oil pan. Figure 44. Removing Gear Pan Marine Transmission Service Manual #1020667...
Page 84: Remove Output Shaft And Gear
Disassembly Twin Disc, Incorporated Remove Output Shaft and Gear Remove output shaft seal carrier attaching screws. Use two of the removed screws as pusher screws to separate seal carrier from housing. Figure 45. Removing Seal Carrier Remove the seal carrier shim pack and O-ring.
Page 85 Disassembly Twin Disc, Incorporated Install three flat washers (1/2” ID or larger) between the seal carrier and housing at each of the ten screw locations. Reinstall the six hexhead capscrews and torque to 60 Nm (45 ft-lb). The gap between the seal carrier and the housing should be approximately 4.5mm (0.17 in).
Page 86 Disassembly Twin Disc, Incorporated Wrap the threads of T-18614-5 with teflon tape and install the tool into one of the threaded output gear holes. Wrap the threads of a 7/16-14 x 2.00 inch screw with teflon tape and install into the other output gear hole.
Page 87 Disassembly Twin Disc, Incorporated Tapered roller bearing cups for front bearings on primary pinion, secondary pinion, and output shaft are an interference fit in their respective bearing bores. Remove these bearing cups only if replacement is required. To remove these bearing cups, weld a light bead around the I.D.
Page 88: Disassembly Of Primary Shaft Or Secondary Shaft (Disassembly Of Secondary Shaft Is Described)
Disassembly Twin Disc, Incorporated Disassembly of Primary Shaft or Secondary Shaft (Disassembly of Secondary Shaft is Described) Remove two piston rings from rear end of shaft. If rear bearing must be removed, remove bearing retaining ring from rear end of shaft. Remove the bearing as follows: Note: Do not remove rear bearing unless bearing must be replaced.
Page 89 Disassembly Twin Disc, Incorporated Remove and disassemble pinion(s). Remove round retaining ring from input end of shaft and remove pinion from shaft. Remove internal retaining ring from input end of pinion and remove straight roller bearing. Note: The straight roller bearing in the bore of the input end of the pinion is a tight fit, and will likely be destroyed during removal.
Page 90 Disassembly Twin Disc, Incorporated Remove tapered roller bearing inner race from shaft. (Bearing supports rear of pinion.) This bearing is a slip fit and should remove easily. Remove internal retaining ring at front of clutch housing and remove clutch backing plate.
Page 91 Disassembly Twin Disc, Incorporated Carefully apply compressed air to hydraulic pressure port to force piston from piston bore. Remove clutch piston. Figure 52. Removing Clutch Piston Remove piston ring from ring groove in shaft (seals I.D. of clutch piston) and piston ring from ring groove in O.D. of clutch piston.
Page 92 Disassembly Twin Disc, Incorporated Selector Valve Disassembly -- Mechanical Valve Steel ball is under pressure from the spring. Care must be taken when removing the cover and orifice plate to prevent loss of steel ball. Remove the orifice plate cover, orifice plate, and check ball.
Page 93 Disassembly Twin Disc, Incorporated Remove the rate-of-rise piston and remove the pressure regulator adjustment shims from the rate-of-rise piston. Figure 55. Removing Shims from Rate of Rise Piston Remove the pressure regulating springs and pressure regulator piston Figure 56. Removing Regulator Springs and Regulator Piston...
Page 94 Disassembly Twin Disc, Incorporated Remove the O-ring plug, detent spring, and detent ball. Figure 57. Removing O-ring Plug, Detent Spring and Ball Mark the lever and the stem to indicate the position the lever was installed on the stem. Loosen the screw clamping the lever to the stem and remove the lever.
Page 95 Disassembly Twin Disc, Incorporated Remove the cover and stem together as a unit. Figure 59. Removing Stem and Cover Together Mark the stop collar and the stem to indicate the position the collar was installed on the stem. While supporting the collar, drive the roll pin out of the collar with a drift punch and remove the collar.
Page 96 Disassembly Twin Disc, Incorporated Remove the O-ring from the stem. Figure 61. Removing O-ring from Stem Remove the thrust bearing and races from the stem. Figure 62. Removing Thrust Bearing and Races from Stem Remove the remaining plugs from the valve body.
Page 97 Disassembly Twin Disc, Incorporated Selector Valve Disassembly -- Electric Valve Steel ball is under pressure from the spring. Care must be taken when removing the cover and orifice plate to prevent loss of steel ball. Loosen and remove four of M8 x 25 socket head capscrews, and remove orifice plate cover and gasket.
Page 98 Disassembly Twin Disc, Incorporated Remove rate-of-rise piston. Note that shims are located between the piston and springs. Figure 64. Rate of Rise Piston (left) and Regulator Springs (right) Remove pressure regulating springs. Remove pressure regulating piston with an external retaining ring pliers.
Page 99 Disassembly Twin Disc, Incorporated Remove four of M8 x 25 socket head capscrews. Remove the cover assembly with gasket from the valve body. Remove the O-ring and oil seal from the cover assembly. Figure 66. Removing O-ring from Cover Remove the two electrical switches from the sides of the valve body and the two steel balls from each of the switch bores in the valve body (some models).
Page 100 Disassembly Twin Disc, Incorporated Remove the dog-point setscrew. Note that the setscrew is retained with MA908 threadlocker. Figure 68. Removing Dogpoint Setscrew Remove the stem from the valve body partially. Remove the thrust washer from the stem. Figure 69. Removing Thrustwasher Remove the stem from the valve body.
Page 101 Disassembly Twin Disc, Incorporated Remove the roll pin (retains the shuttle ball seat) with a needle-nose pliers. Figure 70. Removing Roll Pin Retaining Shuttle Seat Thread a M8x1.25 screw (one of the cover screws works well) into the seat and remove it from the valve body.
Page 102: Disassembly Of Upper Valve Body Half (Electric Section)
Disassembly Twin Disc, Incorporated Disassembly of Upper Valve Body Half (electric section) Remove the Weatherpak connector from the valve body by sliding it in the direction of the opening in the shroud. Mark the wires with the location letters that are on the Weatherpak connector.
Page 103 Disassembly Twin Disc, Incorporated Remove the filter screen from the valve body. Figure 72. Removing Filter Screen Remove the two socket head O-ring plugs from the bores in the end of the valve body. Remove the two spools from the valve body.
Page 104: 1017555 Trolling Valve (Optional Equipment)
Disassembly Twin Disc, Incorporated 1017555 Trolling Valve (Optional Equipment) Remove the trolling valve attaching screws. Figure 73. Removing Trolling Valve Attaching Screws Steel ball is under pressure from the spring. Care must be taken when removing the trolling valve and orifice plate to prevent loss of steel ball.
Page 105 Disassembly Twin Disc, Incorporated Remove the detent setscrew, spring, and detent ball. Figure 74. Removing Detent Setscrew (left) and Detent Spring and Ball (right) Remove the dog-point setscrew from the valve body. Figure 75. Removing Dog-point Setscrew Marine Transmission Service Manual #1020667...
Page 106 Disassembly Twin Disc, Incorporated Slide the stem and adapter out of the valve body together as one piece. Push the stem out of the adapter such that the spring end of the stem exits the adapter first. Note that the inner spring will come out with the stem.
Page 107 Disassembly Twin Disc, Incorporated Remove the inner spring and roll pin from the stem only if replacement of parts is necessary. Remove the washer from the bore of the valve body (some models). Note: the washer may have been removed with the stem.
Page 108 Disassembly Twin Disc, Incorporated Marine Transmission Service Manual #1020667...
Page 109: Cleaning And Inspection
Cleaning and Inspection Twin Disc, Incorporated Cleaning and Inspection Cleaning Note: Replace all oil seals, gaskets, O-rings piston rings, seal rings, snap rings, etc., as a part of any maintenance or overhaul procedure. Replace shims that are damaged or destroyed in disassembly.
Page 110 Cleaning and Inspection Twin Disc, Incorporated Cleaning Bearings Do not remove grease in which new bearings are packed. Thoroughly wash bearings that have been in service. Soak bearings in solvent if they are particularly dirty or filled with hardened grease.
Page 111: Inspection
Cleaning and Inspection Twin Disc, Incorporated Inspection Housings, Cast Parts, and Machined Surfaces Replace cast parts or housings that are cracked. Inspect bores for wear, grooves, scratches and dirt. Remove burrs and scratches with crocus cloth or soft stone. Replace deeply grooved or scratched parts.
Page 112 Cleaning and Inspection Twin Disc, Incorporated Valve Seats Inspect valve seats for burrs, nicks and scratches. If you cannot remove these defects with a crocus cloth, replace the part. Check to see that the valve is seating properly after reworking the valve seat.
Page 113 Cleaning and Inspection Twin Disc, Incorporated Gears Inspect gears for scuffed, nicked, burred or broken teeth. If you cannot remove the defect with a soft stone, replace the gear. Inspect gear teeth for wear that may have destroyed the original tooth shape.
Page 114 Cleaning and Inspection Twin Disc, Incorporated Marine Transmission Service Manual #1020667...
Page 115: Assembly
Assembly Twin Disc, Incorporated Assembly Unless otherwise specified, all torque values listed are for capscrews that have been lubricated on the threads and contact surfaces. The following discussion contains frequent reference to the transmissions parts and components. Refer to Engineering Drawings.
Page 116: Prior To Assembly
Assembly Twin Disc, Incorporated Prior to Assembly Use the following reference: The input side of the transmission is the front and the output side is the rear. Left and right sides are determined by facing the output side of the transmission from the rear.
Page 117: Preliminary Assembly
Assembly Twin Disc, Incorporated Preliminary Assembly Lay the transmission on blocking with the rear side up. Install the seal protector into input shaft front bearing area using a soft hammer. Figure 80. Seal Protector Installation Install the chilled cups for the primary and secondary front tapered roller bearings into their respective bores in the front inner face of the housing.
Page 118 Assembly Twin Disc, Incorporated Measure and record the distance from the machined surface of the housing to the bottom of the bearing cup bore where the oil shield contacts (dimension “A”). Measure and record the thickness of the oil distribution shield at the outer edge (dimension “B”). Measure and record the width of the bearing cup (dimension “C”).
Page 119: Installation Of Output Shaft And Gear
Assembly Twin Disc, Incorporated Installation of Output Shaft and Gear Clean tapered surface of output shaft and tapered bore of output gear. Use OSHA approved cleaning solvent to remove all traces of dirt, grease, oil, etc. Do not touch cleaned surfaces. Loctite® 7070 cleaner is recommended.
Page 120 If no errors are found and the expected advance is out of tolerance, it will be necessary to change parts. Contact the Product Service Department at Twin Disc, Incorporated for assistance. Install T-20023 onto the output shaft and gear.
Page 121: Installation Of Output Shaft Rear Bearing
Assembly Twin Disc, Incorporated Installation of Output Shaft Rear Bearing Install heated rear output shaft tapered roller bearing. Install with small O.D. of bearing to the rear. Press/drive bearing to shaft shoulder using special tool T-18050-323. After bearing cools, press/drive bearing down again to assure that bearing is against shaft shoulder.
Page 122: Output Shaft Tapered Roller Bearing Adjustment
Assembly Twin Disc, Incorporated Output Shaft Tapered Roller Bearing Adjustment To set output shaft bearing clearance, proceed as follows. Install seal carrier without seals or O-ring. Secure seal carrier with capscrews using very little torque on capscrews. Use a taper gauge or feeler gauge to measure gap between rear housing face and flange of output seal carrier.
Page 123 Assembly Twin Disc, Incorporated Install O-ring in groove in O.D. of output seal carrier. Figure 85. Installing O-ring onto Output Seal Carrier Coat O.D. of seals with M2828 anaerobic sealant and install oil seals into output seal carrier using driver T-18050-321. Remove excess sealant that is wiped off as seals are pressed into position.
Page 124 Assembly Twin Disc, Incorporated Pack area between the seals with water pump grease. Figure 86. Packing Cavity Between Output Seals With Grease Install grease fitting if not previously installed. Install established shim pack, aligning screw holes of shims with threaded screw holes of transmission housing.
Page 125 Assembly Twin Disc, Incorporated Install assembled output seal carrier onto housing. Install attaching screws and torque to 122 Nm (90 ft-lb). Figure 88. Installing Seal Carrier Marine Transmission Service Manual #1020667...
Page 126: Assembly And Installation Of Primary And Secondary Shafts
0.117 in.). If calculated advance is not within the range, recheck all measurements and calculations for errors. If no errors are found, contact the Product Service Department at Twin Disc, Incorporated for information. Set secondary transfer gear on fixture T-18050-335 with large diameter of tapered bore up.
Page 127 Note: Actual advance (C-B) must be 1.96 mm to 2.97 mm (0.077 in. to 0.117 in.). If transfer gear has not been advanced as specified above, contact the Product Service Department at Twin Disc, Incorporated for information. Marine Transmission Service Manual #1020667...
Page 128 Assembly Twin Disc, Incorporated Install piston seal ring into groove in secondary shaft. Apply a coat of assembly grease or oil to seal ring. Install piston ring in groove in O.D. of clutch apply piston. Apply a coat of assembly grease or oil to seal ring.
Page 129 Assembly Twin Disc, Incorporated Installation of clutch return springs. Install 16 clutch return spring assemblies into pockets in face of clutch apply piston. (Each assembly consists of one inner and one outer spring.) Install spring retainer over springs with groove toward springs.
Page 130 Assembly Twin Disc, Incorporated Install external retaining ring over shaft to rest against spring retainer. Move shaft assembly to press and install tool T-19998. Press down tool T-19998 to compress springs and expose retaining ring groove of shaft. Keep force on springs and install retaining ring into exposed groove of shaft.
Page 131 Assembly Twin Disc, Incorporated Use driver T-18050-327 and hydraulic press to press rear tapered roller bearing cone onto secondary shaft. Install bearing with large O.D. toward transfer gear and press to seat against transfer gear. Figure 93. Installing Clutch Shaft Rear Bearing Cone...
Page 132 Assembly Twin Disc, Incorporated Install external retaining ring with tapered edge side away from bearing. Beginning with a friction plate, alternately install 9 friction plates and 8 steel plates into clutch housing (transfer gear) against clutch apply piston. Install clutch backplate and internal retaining ring.
Page 133 Assembly Twin Disc, Incorporated Assembly of pinion. Use special tool T-18050-11 to install chilled tapered roller bearing cup into rear of pinion for secondary shaft. Bearing cup is installed with small I.D. of taper toward the front and seated against shoulder of bore in clutch hub.
Page 134 Assembly Twin Disc, Incorporated Install chilled needle roller bearing into bore at front of pinion with T-18050-25. Install internal retaining ring into groove in pinion bore. Figure 96. Installing Internal Retaining Ring Into Pinion Align plates in clutch pack and install pinion on secondary shaft so that external teeth on clutch hub mesh with internal teeth of steel plates in clutch pack.
Page 135 Assembly Twin Disc, Incorporated Install external retaining ring to retain pinion on shaft. Figure 97. Installing External Retaining Ring Onto Clutch Shaft Install two piston rings into grooves at rear end of shaft. Assemble primary shaft. Assembly procedure for primary shaft is exactly the same as for the secondary shaft.
Page 136 Assembly Twin Disc, Incorporated Install oil suction tube into transmission housing, with flange end lifted out of position to allow the secondary shaft assembly to pass by. Figure 98. Installing Suction Tube (left) with Flange Positioned (right) Install clutch shaft assemblies into transmission housing. Use caution to prevent damaging the shafts, gears, and bearings.
Page 137: Installation Of Bearing Carrier
Assembly Twin Disc, Incorporated Installation of Bearing Carrier Install a new O-ring into the flange of the suction tube. Install bearing carrier gasket over dowels onto rear face of housing. Assemble lube relief valve spring and lube relief valve steel ball into lube relief valve housing.
Page 138 Assembly Twin Disc, Incorporated Install lube tube through “keyed” hole in bearing carrier and into machined pocket in front inner face of housing. Rotate tube so elongated “key” of tube fits into corresponding “key” in bearing carrier. Properly installed lube tube will be flush with rear face of bearing carrier.
Page 139: Assembly And Installation Of Manifold
Assembly Twin Disc, Incorporated Assembly and Installation of Manifold Install new O-rings onto the O-ring plugs used for the clutch and lube pressure test ports. Lubricate the O-ring and threads and install the plugs, torquing them to 24 Nm (18 ft-lb). Apply pipe thread sealant to the 1/2”...
Page 140: Primary And Secondary Shaft Bearing Adjustment
Assembly Twin Disc, Incorporated Primary and Secondary Shaft Bearing Adjustment Note: Procedure for setting and checking endplay for primary and secondary shafts is the same. Procedure described and illustrated is for the secondary shaft. Repeat same procedure for the primary shaft.
Page 141 Assembly Twin Disc, Incorporated Check endplay for primary shaft. Repeat steps 1 through 6 on the previous page to adjust endplay for primary shaft. Figure 104. Checking Primary Shaft Bearing Adjustment Marine Transmission Service Manual #1020667...
Page 142: Installation Of Manifold Exterior Components
Assembly Twin Disc, Incorporated Installation of Manifold Exterior Components Install pump suction strainer into bore in manifold, followed by the spring. Figure 105. Installing Suction Strainer into Manifold Install new O-ring onto suction strainer O-ring plug. Apply assembly grease or oil to the O-ring, and install the plug, torquing it to 108 Nm (80 ft-lb).
Page 143 Assembly Twin Disc, Incorporated Install oil pump gasket and oil pump at mounting location at end of secondary shaft. Mesh drive tang on pump shaft with drive slot in secondary shaft. Install attaching screws and torque to 37 Nm (27 ft-lb).
Page 144: Installation Of Top Cover, Oil Gauge, And Oil Pan
Assembly Twin Disc, Incorporated Installation of Top Cover, Oil Gauge, and Oil Pan Install top cover assembly with its gasket. Install attaching screws and torque to 37 Nm (27 ft-lb). Install strainer and breather-filler cap. Figure 107. Installing Strainer and Breather Install oil gauge tube assembly and oil level gauge.
Page 145 Assembly Twin Disc, Incorporated Install the gear pan onto the oil pan and torque the screws to 24 Nm (18 ft-lb). Figure 109. Installing Gear Pan Install two alignment studs into the transmission housing to help guide and align the oil pan. Install a new gasket over the alignment studs.
Page 146: Installation Of Output Flange
Assembly Twin Disc, Incorporated Installation of Output Flange Heat output flange in 300° F (150° C) maximum oven for a half hour to an hour. Install heated output flange. Assure that flange seats solidly against rear tapered roller bearing on output shaft.
Page 147 Assembly Twin Disc, Incorporated Install O-ring to seal output shaft splines and output flange. Figure 112. Installing Output Flange O-ring Install shim pack (developed in step 3) and retainer washer. Install the hexhead capscrews and torque to 434 Nm (320 ft-lb).
Page 148 Stop at whatever position output flange runout is no more than 0.10 mm (0.004 in.). If output flange runout cannot be reduced to acceptable tolerances, contact the Product Service Department at Twin Disc, Incorporated for information/recommendations. Marine Transmission Service Manual #1020667...
Page 149: Assemble Control Valve
Assembly Twin Disc, Incorporated Assemble Control Valve Assembly of Mechanical Control Valve Install the thrust race, thrust bearing, and remaining thrust race onto the stem. Figure 114. Installing Thrust Bearing and Races Install a new oil seal and O-ring into the valve cover.
Page 150 Assembly Twin Disc, Incorporated Install the stop collar onto the stem so that the roll pin holes are aligned as well as the marks made at disassembly. Drive the roll pin into the collar and stem while supporting the stem to prevent damage to the parts.
Page 151 Assembly Twin Disc, Incorporated Install the detent ball, spring and O-ring plug. Torque the plug to 37 Nm (27 ft-lb). Figure 117. Installing Detent Ball, Spring, and O-ring Plug Install the valve lever, aligning the marks made at disassembly. Torque the screw to 15 Nm (11 ft-lb).
Page 152 Assembly Twin Disc, Incorporated Install the pressure regulator adjustment shims into the rate-of-rise piston. Figure 119. Pressure Regulator Adjustment Shims Install the rate-of-rise piston (with shims) into the valve body. Install the check ball spring shim(s) and spring into the valve body.
Page 153 Assembly Twin Disc, Incorporated Place one orifice plate gasket, the check ball, and the orifice plate onto the valve body. Figure 121. Installing Gasket, Check Ball, and Orifice Plate Install the remaining gasket and orifice plate cover onto the valve body.
Page 154 Assembly Twin Disc, Incorporated Assembly of Electrical Control Valve (upperbody half) Install one dowel pin (large diameter) into each of the two bores of the valve body. Install one spring into each of the two bores of the valve body.
Page 155 Assembly Twin Disc, Incorporated Assembly of Electrical Control Valve (lower body half) Install the steel shuttle ball into its bore in the valve body. Install the O-ring onto the shuttle ball seat. Apply lubricant such as Dow Corning 200® 30,000cSt fluid to the O- ring, and install the seat into the valve body.
Page 156 Assembly Twin Disc, Incorporated Apply MA908 threadlocker to the threads of the dog-point setscrew and install. Tighten the dog-point setscrew until snug, then back off 1/2 turn. Figure 124. Installing Dogpoint Setscrew Install the steel detent ball into the valve body.
Page 157 Assembly Twin Disc, Incorporated Install the thrust bearing and races (thrust washer on earlier units) over the end of the stem. Press the oil seal into the cover assembly until flush with the adjacent cover surface. Install the O-ring into the counterbore in the cover assembly.
Page 158 Assembly Twin Disc, Incorporated Install pressure regulating springs into valve body and into piston spring pocket. Install the shims that were removed into the bore of the rate-of-rise piston. Install the rate-of-rise piston over the springs and into valve body.
Page 159 Assembly Twin Disc, Incorporated Install orifice plate cover and gasket onto valve body. Install cover capscrews and torque to 23 Nm (17 lb-ft). Install gasket over lower valve body half. Set upper valve body half over lower valve body half. Insert the valve attaching screws through valve body halves to keep parts in alignment until installation onto the transmission.
Page 160: Trolling Valve (Optional Equipment)
Assembly Twin Disc, Incorporated Assembly of Trolling Valve (Optional Equipment) Press a new oil seal into the counterbore in the end of the adapter. Install a new O-ring into the groove of the adapter. Figure 129. Installing O-ring onto Adapter Install a new O-ring into the groove of the stem.
Page 161 Assembly Twin Disc, Incorporated Apply assembly grease to the adapter (where it contacts the trolling valve body) and install the adapter into the valve body. Be sure to align the setscrew holes in the adapter with those in the valve body.
Page 162 Assembly Twin Disc, Incorporated Install the detent ball and spring into the remaining hole in the valve body. Apply MA908 threadlocker to the threads of the detent setscrew and install until flush with the valve body. Figure 132. Installing Detent Ball, Spring, and Setscrew Check the torque required to overcome the detent.
Page 163 Assembly Twin Disc, Incorporated Install the steel ball onto the neutral pressure regulating spring. Figure 133. Installing Neutral Pressure Regulating Spring and Ball Install the orifice plate gasket, orifice plate, trolling valve gasket, and trolling valve onto the control valve. Install the attaching screws and torque them to 23 Nm (17ft-lb).
Page 164: Installation Of Transmission External Components
Assembly Twin Disc, Incorporated Installation of Transmission External Components Install control valve ditch plate and gasket (units with optional electric control valve). Torque the ditchplate attaching capscrews to 52 Nm (38 ft-lb). Install control valve and gasket. Torque the valve attaching capscrews to 54 Nm (40 ft-lb).
Page 165 (0.012 in) for both a SAE #0 and SAE #1 housing. Note: Should total indicator runout exceed stated limits, contact the Product Service Department of Twin Disc, Incorporated for information and recommendations. Slide input coupling onto splines of input shaft. If the unit is to be shipped with the coupling on the shaft, it must be attached to prevent it from sliding off and causing damage.
Page 166 Assembly Twin Disc, Incorporated Marine Transmission Service Manual #1020667...
Page 167: Installation
Consequently, the driven component should be removed and the source of interference found and corrected. Twin Disc will not be responsible for system damage caused by engine to Twin Disc component interference regardless of the cause of interference.
Page 168: Alignment (Also Reference Sae J-1033 And J-617)
Installation Twin Disc, Incorporated Alignment (also reference SAE J-1033 and J-617) Bolt a thousandths increment dial indicator or gauge to the engine flywheel so that the indicator is perpendicular to the face of the engine flywheel housing, and the indicator stem is riding on the face of the flange.
Page 169 Installation Twin Disc, Incorporated Table 9. Total Indicator Readings for Engine Flywheel Housing Flange Face Deviations and Bore Eccentricity SAE Housing Number mm (in) 0.48 (0.019) 0.41 (0.016) 0.36 (0.014) 0.30 (0.012) 0.28 (0.011) 0.25 (0.010) 0.23 (0.009) 0.20 (0.008) 0.18 (0.007)
Page 170 Installation Twin Disc, Incorporated Rotate the engine flywheel and note the bore eccentricity of the engine flywheel-housing bore. See the previous Table for allowable tolerances. Bolt a thousandths dial indicator or gauge to the engine flywheel housing so that the indicator is perpendicular to the engine flywheel, and the indicator tip is riding on the inner face of the flywheel.
Page 171 Installation Twin Disc, Incorporated With the indicator mounted as in the paragraph above, adjust the indicator tip so that it will ride on the driving ring pilot bore of the engine flywheel. Rotate the flywheel. The driving ring pilot bore eccentricity of the engine flywheel should not exceed 0.13 mm (0.005 in) maximum...
Page 172: Installation
Installation Twin Disc, Incorporated Installation Alignment Proper alignment of an engine and marine unit is critical, both during the initial installation and at frequent intervals during the life of the boat. It is rather common for a boat to change its form with various loads and with age. Engine and shaft alignment can also change on a boat due to varying loads and the boat’s age.
Page 173 Installation Twin Disc, Incorporated Set the indicator gauge at zero (0). Lift the marine gear with a hoist, or other suitable means, and place the unit in position against the engine flywheel housing. Secure the flange of the marine gear main housing to the engine flywheel housing.
Page 174 Installation Twin Disc, Incorporated Engine and Marine Transmission Alignment When mounting the engine and transmission in the boat, all of the mounting pads on both the engine and transmission must be used. Failure to do so may result in damage to the transmission or the engine flywheel housing.
Page 175 Installation Twin Disc, Incorporated When a heavy boat is dry-docked, it naturally undergoes some bending. Therefore, it is always good practice to unbolt the marine transmission coupling to prevent bending of the shaft. With the engine and transmission in position on the engine bed, arrangements must be made to have a controlled lifting or lowering of each of the four corners of the engine.
Page 176 Installation Twin Disc, Incorporated As the engine and marine transmission come into their aligned position, it will be possible to mate the output flange and propeller coupling, and prepare for bolting together. Care should be taken not to burr or mar this connection because the fit is very critical.
Page 177 Installation Twin Disc, Incorporated Figure 145. Checking Output Flange Pilot Eccentricity Some boats are not structurally rigid and some carry their load in such a way that they will “hog” or go out of normal shape with every loading and unloading.
Page 178 Always use the alignment procedures recommended by the coupling manufacturer. Torsional Input Couplings Installation - For Models Provided by Twin Disc Be sure the internal retaining ring is properly installed inside the torsional input coupling hub. See Engineering Drawings section of this manual for correct ring location.
Page 179: Gears
CENTAFLEX ® -R Assembly instructions on flange mounted gears CAUTION- Before you start the coupling assembly Check there is axial play in each direction of the engine crankshaft to ensure the engine thrust bearings are not loaded. Record the result. Assembly Method Mount the gear half of the coupling to the gearbox input shaft as the design dictates.
Page 180 Remove the coupling flange (outer part) and bolt it to the engine flywheel. Torque tighten using the engine manufacturers recommendation, but in the absence of it, the table below gives gene- ral guidelines. Coupling Flange to Engine Flywheel Bolts. These bolts are not supplied with the CENTAFLEX - R Coupling, but where no instructions are available from the engine supplier, the following can be used as a guide.
Page 181 Installation Twin Disc, Incorporated Propeller Shaft Before any attempt to align the engine and gearbox to the propeller shaft, proper alignment of the propeller shaft must be determined. This includes alignment of the propeller shaft through all struts and intermediate bearings. Failure to properly align the propeller shaft may result in premature wear on bearings, vibrations, or possible damage to other components.
Page 184 Installation Twin Disc, Incorporated Mechanical Controls Movement of the operator’s selector lever to the forward, neutral or reverse position must result in the transmission control valve selector being positioned in the forward, neutral or reverse detent location. Cables and linkages must be...
Page 185: Special Tools
Special Tools Twin Disc, Incorporated Special Tools List of Special Tools The following pages include the special tool drawings that are specific to this model. The special tool drawings included are listed below and continue on the following page. T-18050-11...
Page 186 Special Tools Twin Disc, Incorporated Lifting Bracket for Clutch Removal in Boat T-18050-772 Bearing Driver T-19987 Output Gear Lifting Fixture Marine Transmission Service Manual #1020667...
Page 187: Bearing Driver T-18050-11
Special Tools Twin Disc, Incorporated Bearing Driver T-18050-11 Marine Transmission Service Manual #1020667...
Page 188: Driver T-18050-25
Special Tools Twin Disc, Incorporated Driver T-18050-25 Marine Transmission Service Manual #1020667...
Page 189: Bearing Driver T-18050-183
Special Tools Twin Disc, Incorporated Bearing Driver T-18050-183 Marine Transmission Service Manual #1020667...
Page 191: Bearing Driver T-18050-323
Special Tools Twin Disc, Incorporated Bearing Driver T-18050-323 Marine Transmission Service Manual #1020667...
Page 192: Bearing Driver T-18050-327
Special Tools Twin Disc, Incorporated Bearing Driver T-18050-327 Marine Transmission Service Manual #1020667...
Page 193: Bearing Driver T-18050-335
Special Tools Twin Disc, Incorporated Bearing Driver T-18050-335 Marine Transmission Service Manual #1020667...
Page 196: Oil Injection Tool T-18614-5
Special Tools Twin Disc, Incorporated Oil Injection Tool T-18614-5 Marine Transmission Service Manual #1020667...
Page 204: Lifting Bracket For Clutch Removal In Boat
Special Tools Twin Disc, Incorporated Lifting Bracket for Clutch Removal in Boat Marine Transmission Service Manual #1020667...
Page 206 Special Tools Twin Disc, Incorporated Notes Marine Transmission Service Manual #1020667...
Page 208 Special Tools Twin Disc, Incorporated Notes Marine Transmission Service Manual #1020667...
Page 209 Illustrations Twin Disc, Incorporated Illustrations List of Illustrations The following pages include illustrations that are specific to this model. The illustrations included are listed below. Note: Any part numbers listed in the following illustrations are for reference only. Please refer to your bill of material for part numbers specific to your model.
Page 210 18 19 20 21 22 23 24 10 11 12 13 15 16 17...
Page 211 Item Qty. Description Bearing, tapered roller (primary and secondary shaft front bearing) Ring, internal retaining Ring, external retaining (primary and secondary shaft @ needle bearing) Shaft assembly, secondary Bearing, needle roller Pinion assembly O-ring (speed pick-up port plug) Plug (5/8-18 speed pick-up port) Bearing, tapered roller (primary and secondary pinion rear bearing) Backplate, clutch...
Page 212: Suction Strainer
Illustrations Twin Disc, Incorporated Suction Strainer Item Qty. Description Strainer, suction Spring, compression O-ring (suction tube) Tube assembly, suction O-ring (suction strainer plug) Plug (suction strainer) Marine Transmission Service Manual #1020667...
Page 213: Oil Filter
Illustrations Twin Disc, Incorporated Oil Filter Item Qty. Description Tube, lubrication Filter, oil Gasket (filter bypass valve) Screw, hex head cap (filter bypass valve) Cover (filter bypass valve) Spring, compression (filter bypass valve) Poppet, filter bypass Ball, steel (lube relief valve)
Page 214: Transmission Rear View
Illustrations Twin Disc, Incorporated Transmission Rear View Marine Transmission Service Manual #1020667...
Page 215 Illustrations Twin Disc, Incorporated Item Qty. Description Screw, hex head cap (oil pump) Tube assembly, oil gauge Oil gauge Tag, oil gauge Screw, drive (identification plate) Plug ass’y, O-ring (secondary clutch press. port) Plug, pipe (lube pressure test port) Screw, socket head cap (12pt on some models)
Page 216: Transmission Section View
Illustrations Twin Disc, Incorporated Transmission Section View Marine Transmission Service Manual #1020667...
Page 217 Illustrations Twin Disc, Incorporated Item Qty. Description Cover, bottom Pan, gear Screw, hex head cap (gear pan to cover) Washer, flat (gear pan to cover) Screw, hex head cap (cover) Gasket Setscrew (output gear to output shaft) Housing Shield, oil distribution...
Page 218 SERVICE REFERENCE: SERVICE REFERENCE:...
Page 219 Item Qty. Description Coupling assembly, SAE #1 Screw, hex head cap (input coupling hub) Nut, hex (input coupling hub) Hub, splined coupling (close coupled units) Ring, internal retaining Coupling assembly, SAE #0 Coupling assembly, SAE #1 Ring, internal retaining Coupling assembly, SAE #0 Element (to service item 127 or 129) Hub, splined coupling (free standing units) Ring, internal retaining...
Page 220 141 140 139 138 137 136 169 168 167 166 165 164 163...
Page 221 Item Qty. Description Race, thrust O-ring (valve cover) Collar, stop Pin, roll Screw, Socket head Lever, shift Screw, hex head Seal, oil Cover, valve Gasket (valve cover) Spring (detent) O-ring Plug, O-ring Plug (optional oil inlet) Plug Piston (pressure regulating) Screw (short) (12pt head or socket head depending on model) Screw (long) (12pt head or socket head depending on model) Spring, outer pressure regulating...
Page 222 170 171 172 173 174 175 176 177 178...
Page 223 Item Qty. Description Race, thrust O-ring (valve cover) Collar, stop Pin, roll Screw, Socket head Lever, shift Screw, hex head Seal, oil Cover, valve Gasket (valve cover) Spring (detent) O-ring Plug, O-ring Plug (optional oil inlet) Plug Piston (pressure regulating) Screw (short) (12pt head or socket head depending on model) Spring, outer pressure regulating Closure, plastic (valve to manifold screw holes)
Page 224 Illustrations Twin Disc, Incorporated Notes Marine Transmission Service Manual #1020667...
Page 226 Illustrations Twin Disc, Incorporated Notes Marine Transmission Service Manual #1020667...
Page 228 Illustrations Twin Disc, Incorporated Notes Marine Transmission Service Manual #1020667...
Page 229 Engineering Drawings Twin Disc, Incorporated Engineering Drawings List of Engineering Drawings The following pages include the engineering drawings that are specific to this model. The engineering drawings included are listed below . Note: Any part numbers listed in the following engineering drawings are for reference only.
Page 230 Engineering Drawings Twin Disc, Incorporated Marine Transmission Service Manual #1020667...
Page 248 Engineering Drawings Twin Disc, Incorporated Notes Marine Transmission Service Manual #1020667...
Page 250 #1020667 07/02 TWIN DISC, INCORPORATED RACINE, WISCONSIN 53403, U.S.A. 262-638-4000/262-638-4482 (FAX) WWW.TWINDISC.COM...

Twin Disc MG-5170DC Service Manual

Quick Links

Need help?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for Twin Disc MG-5170DC

Summary of Contents for Twin Disc MG-5170DC

Table of Contents