Allison Transmission 4000, 500 Service Manual

Operator’s Manual

AT, MT, HT Series On-Highway Transmission

OM1334EN

MT4108EN

Operator’s

Manual

Allison Transmission

AT 540 AT 542(N)(R)(NFE AT 54 AT 545(N)(R AT 1542 AT 1545P(N MT 640, MT(B) 643, MT 643R, 644, 64 MT 650, MT(B) 653, 654C HT 740(D)(RS)(FS HT 747(D HT 750CRD, HT 750DR (DB)(RS HT 750DRI, HT 750DRD (DB HT 754CRD, HT 754CR (RS)

OM1334EN

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Printed in U.S.A.

Alli son Tr ansmi ssio n, In c.

P.O. Box 894 Indiana poli s, In dian a 4 6206 -0894

www.al lisontran smission. com

i

February, 2001

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 . Consequently, Allison Transmission has not undertaken any such broad evaluation. Accordingly, ANYONE WHO USES A SERVICE PROCEDURE OR TOOL WHICH IS NOT RECOMMENDED BY ALLISON TRANSMISSION MUST ﬁrst be thoroughly satisﬁed that neither personal safety nor equipment safety will be jeopardized by the service methods selected.

Proper service and repair is important to the safe, reliable operation of the equipment. The service procedures recommended by Allison Transmission and described in this handbook are effective methods for performing service operations. Some of these service operations require the use of tools specially designed for the purpose. The special tools should be used when and as recommended.

Three types of headings are used in this manual to attract your attention. These warnings and cautions advise of speciﬁc methods or actions that can result in personal injury, damage to the equipment, or cause the equipment to become unsafe.

WARNING:

etc., if not correctly followed, could result in personal injury or loss of life.

CAUTION:

practice, etc., if not strictly observed, could result in damage to or destruction of equipment.

NOTE:

essential to highlight.

A warning is used when an operating procedure, practice,

A caution is used when an operating procedure,

A note is used when an operating procedure, practice, etc., is

TRADEMARK INFORMATION

DEXRON® is a registered trademark of General Motors Corporation. TranSynd™ is a trademark of Castrol Ltd.

ii

INTRODUCTION

KEEPING THAT ALLISON ADVANTAGE

STOP

RR

YIELD

SPEED

ZONE

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. This handbook will help you gain maximum beneﬁts from your Allison-equipped vehicle.

1

TYPICAL AT, MT, AND HT MODEL TRANSMISSIONS

AT Model Transmission

MT Model Transmission

HT Model Transmission

2

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. The clutches and gear sets provide multiple speeds forward and one speed reverse.

The torque converter lockup clutch, for maximum fuel economy, engages automatically after the vehicle is moving. All models in this manual, except AT 500, have a lockup clutch.

TORQUE CONVERTER

The torque converter consists of three elements — pump, turbine, and stator. The pump is the input element and is driven by the engine. The turbine is the output element and is driven by ﬂuid from the pump, or directly by the pump when the lockup clutch is engaged. The stator is the reaction (torque multiplying) element.

The torque converter is continuously ﬁlled with ﬂuid. The pump, driv en by the engine, directs the ﬂuid against the turbine vanes, which causes the turbine to rotate. The turbine returns the ﬂuid through the stator, which redirects the ﬂow so that ﬂuid strik es the pump vanes in the same direction that the pump is rotating. As the pump turns faster in relation to the turbine, the velocity of the ﬂuid increases and so does the torque multiplication.

As the speed of the turbine approaches the speed of the pump, the ﬂuid ﬂow starts striking the back sides of the stator vanes. This causes the stator to free wheel in the same direction as the pump and turbine. When this occurs, the torque multiplication stops and the converter functions as a ﬂuid coupling.

LOCKUP CLUTCH (AT 1500, MT(B) 600, HT 700)

The lockup clutch consists of three elements — piston, clutch plate, and backplate. The piston and backplate are driven by the engine. The clutch plate, located between the piston and backplate, is splined to the converter turbine.

The lockup clutch automatically engages after the vehicle is moving and the torque multiplication demand is low. Engagement of the lockup clutch mechanically connects the torque converter pump to the turbine and pro vides a direct dri ve from the engine to the transmission. The lockup clutch automatically releases at lower vehicle speeds. When the lockup clutch is not engaged, driv e from the engine is transmitted hydraulically through the converter to the transmission gearing.

3

Because the converter lockup engagement and release are designed to ﬁt the v ehicle’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. Some models have lockup available in all ranges. Others have lockup available in the upper ranges. Some models have modulated lockup, which provides better engine braking by delaying lockup disengagement during closedthrottle operation. For speciﬁc information on the lockup characteristics of your transmission, contact your dealer or distributor .

Lockup engagement, like range shifts, may be felt under some conditions. The driv er who counts shifts should not confuse lockup with a range change. A little driving experience with the Allison automatic will enable the driver to distinguish between the two kinds of shifts.

4

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.

R

N

D

4

3

2

1

These are some of the typical shift selectors you may ﬁnd in Allison-equipped vehicles. The range selector in your vehicle may v ary from these or may have

1

(First Range) at the top and R (Reverse) at the bottom. Some models may hav e

a P (Park) position. The best performance will be obtained by using the correct range for each driving

condition. The following table illustrates shift patterns for the v arious models and indicates the page that explains the shift pattern for your vehicle.

R

N

D

R

N

D

2-4

3

2

1

Typical Shift Selector Labeling

2-3

2

1

R

N

D

2-4

2

1

V01958.01

5

ALLISON AUTOMATICS

MT 640, A T 500 Series And A T 1500 Series

MT(B) 643,

MT 643R,

MT(B) 644◊,

MT(B) 647

MT 650, MT(B) 653DR

HT 740, HT 747

HT 750CR, HT 754CR, MT(B) 654CR

HT 750DR

◊

(DR DB)

P*

R

N

V01959

Park — — — — —

Reverse Reverse Reverse Reverse Reverse Reverse

Neutral Neutral Neutral Neutral Neutral Neutral

1–4 1–4 2–5 1–4 1–5 2–5

1–3 1–3 2–4 1–3 1–4 2–4

+

1–2

1 1 1 1 1–2 2

————1 1

(Pages 7-10) (Pages 9-10) (Pages 11-12)(Pages 9-10) (Pages 13-14) (Pages 15-16)

Typical AT, MT, HT Shift Selector Positions

1–2 2 (2–3**) 1–2 1–3 2–3

When your vehicle is equipped with an Allison automatic, it is not necessary to select the right moment to upshift or downshift during the changing road and trafﬁc conditions. The Allison automatic does it for you. A knowledge of the ranges av ailable at your shift selector will make control of the vehicle and your job even easier.

When the shift selector has no P (Park) provision, always put the selector in

N (Neutral) and apply the parking brake (or service brakes if the vehicle is not

equipped with a parking brake) to hold the vehicle when it is unattended and before turning off the engine.

* Available on AT 500 Series and AT 1500 Series models only (refer to Page 7).

+ This position not present on models with P (Park).

** Optional.

◊

Without second gear start.

6

R

GE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITH A

RAN

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:

• Put the transmission in N (Neutral)...and

• Apply the parking brake and emergency brakes and mak e sure the y are

properly engaged...and

• Chock the wheels and take any other steps necessary to keep the

vehicle from moving.

P

R

N

D

This activates the vehicle parking brake and at the same time puts the transmission in neutral. Use this position when you start the engine. If the engine starts in any other position, except switch is malfunctioning.

Use this to back the vehicle. Completely stop the vehicle before shifting from a forward range to range. The reverse w arning signal is acti v ated when the shift selector is in this position. Reverse has only one range. Re verse operation also pro vides the greatest tractive advantage.

WARNING: If you let the vehicle coast in N (Neutral), there is no engine braking and you could lose control. Coasting can also cause severe transmission damage. To help avoid injury and property damage, do not allow the vehicle to coast in N (Neutral).

Neutral position is used during stationary operation of the power takeoff (if your vehicle is equipped with a PTO).

The transmission will initially attain 1st range and, as vehicle speed increases, the transmission will upshift to 2nd range, 3rd range, and 4th range automatically. As the vehicle slows down, the transmission will downshift to the correct range automatically.

WARNING: If you just downshift or just use service brakes when going downhill, you can lose control and cause injury and property damage. To help avoid loss of control, use a combination of downshifting, braking, and other retarding devices. Downshifting to a lower transmission range increases engine braking and helps you to maintain control. The transmission has a feature to prevent automatic upshifting abo ve the lower range selected. However, during downhill operation, if engine governed speed is exceeded in the lower range, the transmission may upshift to the next higher range. This will reduce braking and could cause a loss of control. Apply the vehicle brakes or other retarding device to prev ent e xceeding engine governed speed in the lower range selected.

(Reverse) or from R (Reverse) to a forward

N (Neutral), the neutral start

7

D

GE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITH A

RAN

SECOND NEUTRAL (PARK) (cont’d)

3

2

1

Occasionally , the road, load, or traf ﬁc conditions will mak e it desirable to restrict the automatic shifting to a lower range. (When conditions improve, return the selector to the normal positions also provide greater engine braking for going down grades (the lower the range, the greater the braking effect).

Use this range when pulling through mud and snow or dri ving up or down steep grades. This range provides the vehicle with maximum driving power and maximum engine braking power.

(Drive) position.) These

8

R

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. If you must leave the engine running, do not leave the vehicle until you:

• Put the transmission in N (Neutral)...and

• Apply the parking brake and emergency brakes and mak e sure the y are

properly engaged...and

• Chock the wheels and take any other steps necessary to keep the

vehicle from moving.

R

N

D

Use this to back the vehicle. Completely stop the vehicle before shifting from a forward range to range. The reverse w arning signal is acti v ated when the shift selector is in this position. Reverse has only one range. Reverse operation also provides the greatest tractive advantage.

WARNING: If you let the vehicle coast in N (Neutral), there is no engine braking and you could lose control. Coasting can also cause severe transmission damage. To help avoid injury and property damage, do not allow the vehicle to coast in N (Neutral).

Use this position when you start the engine. If the engine starts in any other position, the neutral start switch is malfunctioning. Neutral position is also used during stationary operation of the power takeoff (if your vehicle is equipped with a PTO).

The transmission will initially attain 1st range and, as vehicle speed increases, the transmission will upshift to 2nd range, 3rd range, and 4th range automatically. As the vehicle slows down, the transmission will downshift to the correct range automatically.

WARNING: If you just downshift or just use service brakes when going downhill, you can lose control and cause injury and property damage. To help avoid loss of control, use a combination of downshifting, braking, and other retarding devices. Downshifting to a lower transmission range increases engine braking and helps you to maintain control. The transmission has a feature to prevent automatic upshifting abo ve the lower range selected. However, during downhill operation, if engine governed speed is exceeded in the lower range, the transmission may upshift to the next higher range. This will reduce braking and could cause a loss of control. Apply the vehicle brakes or other retarding device to prev ent e xceeding engine governed speed in the lower range selected.

(Reverse) or from R (Reverse) to a forward

9

D

RANGE SELECTION — AT 500 SERIES AND AT 1500 SERIES WITHOUT A SECOND NEUTRAL (PARK)

MT 643R, MT(B) 644, MT 647; HT 740, HT 747

; MT 640, MT(B) 643,

(cont’d)

3

2

1

Occasionally , the road, load, or traf ﬁc conditions will mak e it desirable to restrict the automatic shifting to a lower range. (When conditions improve, return the selector to the normal positions also provide greater engine braking for going down grades (the lower the range, the greater the braking effect).

Use this range when pulling through mud and snow or dri ving up or down steep grades. This range provides the vehicle with maximum driving power and maximum engine braking power.

(Drive) position.) These

10

Allison Transmission 4000, 500 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

WARNINGS, CAUTIONS, AND NOTES

TRADEMARK INFORMATION

TABLE OF CONTENTS

INTRODUCTION

KEEPING THAT ALLISON ADVANTAGE

TYPICAL AT, MT, AND HT MODEL TRANSMISSIONS

AT Model Transmission

MT Model Transmission

HT Model Transmission

A BRIEF DESCRIPTION OF THE ALLISON AUTOMATIC

TORQUE CONVERTER

LOCKUP CLUTCH (AT 1500, MT(B) 600, HT 700)

SHIFT SELECTORS

ALLISON AUTOMATICS

Typical AT, MT, HT Shift Selector Positions