Allison Transmission AT Series Operator's Manual
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Allison Transmission AT Series Operator's Manual

On-highway transmissions
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Operator's Manual
AT, MT, HT Series
On-Highway Transmissions
OM1334EN

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Summary of Contents for Allison Transmission AT Series

  • Page 1 Operator’s Manual AT, MT, HT Series On-Highway Transmissions OM1334EN...
  • Page 2 OM1334EN Operator’s Manual Allison Transmission AT 540 AT 542(N)(R)(NFE) AT 543 AT 545(N)(R) AT 1542P AT 1545P(N) MT 640, MT(B) 643, MT 643R, 644, 647 MT 650, MT(B) 653, 654CR HT 740(D)(RS)(FS) HT 747(D) HT 750CRD, HT 750DR (DB)(RS) HT 750DRI, HT 750DRD (DB)

  • Page 3: Warnings, Cautions, And Notes

    IT IS YOUR RESPONSIBILITY to be completely familiar with the warnings and cautions described in this handbook. It is, however, important to understand that these warnings and cautions are not exhaustive. Allison Transmission could not possibly know, evaluate, and advise the service trade of all conceivable ways in which service might be done or of the possible hazardous consequences of each way.

  • Page 4: Table Of Contents

    TABLE OF CONTENTS Page INTRODUCTION Warnings, Cautions, And Notes ........Keeping That Allison Advantage .
  • Page 5 Allison Transmission Distributors ........39...

  • Page 6: Keeping That Allison Advantage

    INTRODUCTION KEEPING THAT ALLISON ADVANTAGE STOP SPEED Y I E L D Y I E L D ZONE HILL HILL V01724 Allison automatics provide many advantages for the driver who must “stop and go” or change speeds frequently. Driving is easier, safer, and more efficient. These automatics are rugged and are designed to provide long, trouble-free service.

  • Page 7: Typical At, Mt, And Ht Model Transmissions

    TYPICAL AT, MT, AND HT MODEL TRANSMISSIONS AT Model Transmission MT Model Transmission HT Model Transmission...

  • Page 8: A Brief Description Of The Allison Automatic

    A BRIEF DESCRIPTION OF THE ALLISON AUTOMATIC Allison automatics described in this manual include a hydraulic torque converter, a planetary gear train, and a hydraulic control system which supplies fluid under pressure to apply the clutches and automatically shift ranges. The torque converter multiplies engine torque during starts and acts as a hydraulic cushion between the engine and gearing.
  • Page 9 Because the converter lockup engagement and release are designed to fit the vehicle’s vocation, there are many variations among transmission assemblies. Lockup speeds are determined by many factors. Among these are transmission-engine match, transmission-vehicle match, model year, throttle position, and calibration of the hydraulic system.

  • Page 10: Shift Selectors

    SHIFT SELECTORS The vehicle manufacturers may choose different types of shift selectors for their equipment. Different transmission models may also require different designations on the shift selectors. V01958.01 Typical Shift Selector Labeling These are some of the typical shift selectors you may find in Allison-equipped vehicles.

  • Page 11: Allison Automatics

    ALLISON AUTOMATICS MT 640, AT 500 MT(B) 643, Series And MT 643R, MT 650, HT 750CR, AT 1500 MT(B) 644◊, MT(B) HT 740, HT 754CR, HT 750DR Series MT(B) 647 653DR HT 747 MT(B) 654CR◊ (DR DB) Park — — —...

  • Page 12: Range Selection - At 500 Series And At 1500 Series With A Second Neutral (Park)

    RAN GE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITH A SECOND NEUTRAL (PARK) WARNING: If you leave the vehicle and the engine is running, the vehicle can move suddenly and you or others could be injured. If you must leave the engine running, do not leave the vehicle until you: •...
  • Page 13 RAN GE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITH A SECOND NEUTRAL (PARK) (cont’d) Occasionally, the road, load, or traffic conditions will make it desirable to restrict the automatic shifting to a lower range. (When conditions improve, return the selector to the normal D (Drive) position.) These positions also provide greater engine braking for going down grades (the lower the range, the greater the braking effect).
  • Page 14 RANGE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITHOUT A SECOND NEUTRAL (PARK) ; MT 640, MT(B) 643, MT 643R, MT(B) 644, MT 647; HT 740, HT 747 WARNING: If you leave the vehicle and the engine is running, the vehicle can move suddenly and you or others could be injured.
  • Page 15 RANGE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITHOUT A SECOND NEUTRAL (PARK) ; MT 640, MT(B) 643, MT 643R, MT(B) 644, MT 647; HT 740, HT 747 (cont’d) Occasionally, the road, load, or traffic conditions will make it desirable to restrict the automatic shifting to a lower range.

  • Page 16: Range Selection - Mt 650; Mt(B) 653Dr

    RANGE SELECTION — MT 650; MT(B) 653DR WARNING: If you leave the vehicle and the engine is running, the vehicle can move suddenly and you or others could be injured. If you must leave the engine running, do not leave the vehicle until you: •...
  • Page 17 RANGE SELECTION — MT 650; MT(B) 653DR (cont’d) Use this position for vehicle speed control up or down steep grades or for other undesirable driving conditions. 2–3 This is the creeper range — select this for off-highway operation. Use the creeper for pulling through mud or snow.

  • Page 18: Range Selection - Ht 750Cr, Ht 754Cr, Mt(B) 654Cr

    RANGE SELECTION — HT 750CR, HT 754CR, MT(B) 654CR WARNING: If you leave the vehicle and the engine is running, the vehicle can move suddenly and you or others could be injured. If you must leave the engine running, do not leave the vehicle until you: •...
  • Page 19 RANGE SELECTION — HT 750CR, HT 754CR, MT(B) 654CR (cont’d) Occasionally, the road, load, or traffic conditions will make it desirable to restrict the automatic shifting to a lower range. (When conditions improve, return the selector to the normal D (Drive) position.) The positions also provide a greater engine braking for going down grades (the lower the range, the greater the braking effect).

  • Page 20: Range Selection - Ht 750Dr, Ht 750Dr Db

    RANGE SELECTION — HT 750DR, HT 750DR DB WARNING: If you leave the vehicle and the engine is running, the vehicle can move suddenly and you or others could be injured. If you must leave the engine running, do not leave the vehicle until you: •...
  • Page 21 RANGE SELECTION — HT 750DR, HT 750DR DB (cont’d) Use this position for vehicle speed control up or down steep grades or for other undesirable road conditions. This is the creeper range — select this for off-highway operation. Use the creeper for pulling through mud or snow.

  • Page 22: Driving Tips

    DRIVING TIPS THROTTLE CONTROL The position of the throttle influences the automatic shifting. At wide open throttle, the transmission will upshift automatically near the governed speed of the engine. At part throttle, shifts will occur at a lower engine speed. When modulated lockup is provided, closed-throttle operation delays the release of the lockup clutch to provide additional engine braking at lower vehicle speeds.

  • Page 23: Using The Engine For Downhill Braking To Slow The Vehicle Or Equipment

    USING THE ENGINE FOR DOWNHILL BRAKING TO SLOW THE VEHICLE OR EQUIPMENT WARNING: The transmission incorporates a hold feature to pro- hibit upshifting above the range selected during normal driving. For downhill operation, select a lower transmission range. However, if engine governed speed is exceeded in the held range, the transmis- sion may upshift to the next higher range and damaging engine overspeed is a possibility.
  • Page 24 Hydraulic retarders are available on some models of the AT 500, MT 600, and HT 700 Series transmissions. The AT 500 retarder and the MT 643R input retarder are located between the torque converter and the transmission gearing. The MT 600 output retarder is installed on the rear of the transmission in place of the output housing.

  • Page 25: Auxiliary Transmission

    The HT 700 Series retarder, located between the torque converter and the transmission gearing, provides hydraulic retardation capabilities to slow the vehicle. Maximum retarder effect in this series occurs at high input speed. Selecting a lower hold range position when using this type retarder is recommended for maximum effect. Depending on the vehicle retarder apply system used, partial retarder application is available when maximum application is not needed.

  • Page 26: Driving On Ice Or Snow

    DRIVING ON ICE OR SNOW WARNING: Do not use the retarder during inclement weather or when road surfaces are slippery. De-energize the retarder at the master control switch. The ALLISON AUTOMATIC continuously provides proper balance between required power and good traction. The driver can have better control of his vehicle because of this smooth, constant flow of power through the drivetrain.
  • Page 27 The transmission must never be operated above any of the maximum temperatures shown in the table. Extended operations at low vehicle speeds with the engine at full throttle or during extended use of the hydraulic retarder can cause excessively high fluid temperatures in the transmission.

  • Page 28: Power Takeoff Operation

    POWER TAKEOFF OPERATION ENGINE-DRIVEN PTO Some models provide PTO mountings on the top and side of the torque converter housing. The type of PTO installed will determine the operating procedures. If the PTO driven gear is in constant mesh with the drive gear in the converter housing, and a friction clutch is used to connect the PTO load, the PTO can be engaged or disengaged at any time (except at engine speeds that exceed drive speed limits imposed on the driven equipment).
  • Page 29 CAUTION: Never engage the PTO by clashing the gear teeth. This may damage the PTO unit and the PTO drive gear teeth. Stop clash- ing by releasing the vehicle brakes and allowing the vehicle to move slightly or by moving the shift selector from a drive range to N (Neutral) and back to a drive range.

  • Page 30: Care And Maintenance

    CARE AND MAINTENANCE PERIODIC INSPECTIONS The ALLISON AUTOMATIC requires minimum maintenance. Careful attention to the fluid level, selector linkage, and throttle (modulator) linkage is most important. For easier inspection, the transmission should be kept clean. Report any abnormal condition to your maintenance personnel. Inspect the transmission for the following.

  • Page 31: Prevent Major Problems

    PREVENT MAJOR PROBLEMS Minor problems can be kept from becoming major problems if you notify maintenance personnel when any of these conditions occur: • Overheating • Shifting feels odd • Transmission leaks fluid • Unusual transmission-related sounds (changes in sound level caused by normal engine thermostatic fan cycling while climbing a long grade with a heavy load have been mistaken for unusual transmission-related sounds).

  • Page 32: Transmission Fluid Check Procedure

    TRANSMISSION FLUID CHECK PROCEDURE WARNING: Take the following precautions so that unexpected, pos- sible sudden vehicle movement is avoided. Whenever it becomes nec- essary to leave the vehicle, even momentarily, while the engine is running, place the transmission shift selector in N (Neutral) or P (Park), set the parking brake and/or emergency brakes and chock the wheels.

  • Page 33: Cold Check

    Check the fluid level by the following procedures and record any abnormal fluid level, milky appearance, or any trace of coolant in the fluid on your maintenance records. Cold Check NOTE: The only purpose of the Cold Check is to determine if the transmission has enough fluid to be safely operated until a Hot Check can be made.

  • Page 34: Hot Check

    Hot Check NOTE: The fluid level rises as the temperature increases. To ensure an accurate check, operate the transmission until the sump fluid temperature is 160–200°F (71–93°C); converter-out temperature is 180–220°F (82–104°C). If a transmission temperature gauge is not present, check fluid level when the engine water temperature gauge has stabilized and the transmission has been operated under load for at least one hour.

  • Page 35: Keeping Fluid Clean

    Consult your Allison Transmission dealer or distributor before using other fluid types; fluid types such as Type F, and universal farm fluids may or may not be properly qualified for use in your Allison transmission. CAUTION: Disregarding minimum fluid temperature limits can re- sult in transmission malfunction or reduced transmission life.

  • Page 36: Mt 643R Transmissions

    fluids with a viscosity of either SAE 30 or SAE 15W-40 are recommended for use in MT 643R transmissions. For specific name brands, contact the local Allison Transmission Regional Office. CAUTION: Disregarding minimum fluid temperature limits can re- sult in transmission malfunction or reduced transmission life.

  • Page 37: Fluid And Filter Change Intervals

    FLUID AND FILTER CHANGE INTERVALS Fluid and filter change frequencies are determined as follows. • Table 3 is a general guide. The fluid must be changed whenever there is evidence of dirt or high temperature indicated by discoloration or strong odor. More frequent changes may be required when operations are subject to high levels of contamination or overheating.

  • Page 38: Fluid Contamination

    Table 3. Fluid and Filter Change Intervals (cont’d) Transmission Fluid Change Internal Sump Governor External Application Filter Filter Auxiliary Filter** MT 643R After first Paper Filter: 20,000 miles After first 5000 miles 5000 miles At every other fluid (32 000 km) (8000 km) then at (8000 km) then change...
  • Page 39 found in the sump or on the magnetic plate in the bottom of the pan (if present), the transmission must be disassembled and closely inspected to find the source. Metal contamination requires complete disassembly of the transmission and cleaning of all internal and external circuits, cooler, and all other areas where the particles could lodge.

  • Page 40: Auxiliary Filter

    If any doubt exists about the cleanup of the cooler, replace the cooler. Consult your nearest Allison Transmission dealer/distributor or the chassis OEM for detailed filter information and availability.

  • Page 41: Customer Service

    The satisfaction and goodwill of the owners of Allison transmissions are of primary concern to Allison Transmission Division (ATD), its distributors, and their dealers. As an owner of an Allison transmission, you have service locations throughout the world that are eager to meet your parts and service needs with: •...
  • Page 42 Therefore, it is suggested the above steps be followed in sequence when experiencing a problem. Your purchase of an Allison Transmission product is greatly appreciated, and it is our sincere desire to assure complete satisfaction.

  • Page 43: Service Literature

    SERVICE LITERATURE Additional service literature is available as shown in Table 5. This service literature provides fully illustrated instructions for the operation, maintenance, service, overhaul, and parts support of your transmission. To ensure that you get maximum performance and service life from your unit, you may order publications from: SGI, Inc.

  • Page 44: Allison Transmission Distributors

    ALLISON TRANSMISSION DISTRIBUTORS EASTERN REGION Atlantic Detroit Diesel-Allison, LLC Penn Detroit Diesel-Allison, Inc. 180 Route 17 South 8330 State Road Lodi, NJ 07644 Philadelphia, PA 19136-2986 201-489-5800 215-335-0500 Covington Detroit Diesel-Allison Western Branch Diesel, Inc. 8015 Piedmont Triad Parkway 3504 Shipwright Street...
  • Page 45 CENTRAL REGION Caribe Detroit Diesel-Allison Inland Diesel, Inc. Division of GT Corporation 13015 West Custer Avenue Ceramic Ind. Park, Campo Rico Ave., Butler, WI 53007-0916 Block C 262-781-7100 Carolina, Puerto Rico 00982 787-750-5000 Central Detroit Diesel-Allison, Inc. Interstate Detroit Diesel 9200 Liberty Drive 2501 East 80th Street Liberty, MO 64068...
  • Page 46 WESTERN REGION Pacific Detroit Diesel-Allison Company Valley Detroit Diesel-Allison, Inc. 7215 South 228th Street 425 South Hacienda Boulevard Kent, WA 98032 City of Industry, CA 91745-1123 253-854-0505 626-333-1243 Sierra Detroit Diesel-Allison, Inc. Williams Detroit Diesel-Allison 1755 Adams Avenue Southwest, Inc. San Leandro, CA 94577-1001 2602 S.

  • Page 47: Allison Transmission Regional Offices

    ALLISON TRANSMISSION REGIONAL OFFICES EASTERN REGION WESTERN REGION 19 Oaklynn Drive 39465 Paseo Padre Parkway P. O. Box 400 Suite 2400 Columbus, NJ 08022-0400 Fremont, CA 94538 609-298-2541 510-498-5208 CENTRAL REGION CANADIAN REGION P. O. Box 894, Speed Code PF06 P.
  • Page 48 OM1334EN 199907 Printed in U.S.A. 200005...

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