Hydra-Matic 4T40-E/4T45-E (MN4/MN5)

Hydra-Matic 4T40-E/4T45-E Transaxle (MN4/MN5)
2003 Model Year

Type:
Four speed front-wheel-drive, electronically controlled, automatic overdrive transaxle with electronically controlled torque converter clutch

Engine Range:
1.5L - 3.1L (MN4)
3.0L - 3.4L (MN5)

Maximum Engine Torque:
190 lb-ft (260 Nm) (MN4)
205 lb-ft (278 Nm) (MN5)

Maximum Gearbox Torque:
325 lb-ft (440 Nm) (MN4)
325 lb-ft (440 Nm) (MN5)

Gear Ratios:

First: 2.957
Second: 1.623
Third: 1.000
Fourth: 0.683
Reverse: 2.143

Maximum Shift Speed:
6500 rpm (MN4)
5800 rpm (MN5)

Maximum Validated Gross Vehicle Weight:
1990 kg (4347 lb)

7-Position Quadrant:
P, R, N, OD, 3, 2, 1

Case Material:
Die cast aluminum

CONTROL SYSTEMS:

Shift Pattern:
(2) Two-way on/off solenoids

Shift Quality:
Variable Bleed Solenoid

Torque Converter Clutch:
Pulse width modulated solenoid control

Converter Size:
245mm (reference) (Diameter of torque converter turbine)

Fluid Type:
DEXIII

Transmission Weight:
Dry: 74.7 kg (164 lb)
Wet: 85.1 kg (187.6 lb)

Fluid Capacity (Approximate):
Bottom Pan Removal: 7.0L (7.4 qt)

Complete Overhaul:
10.0L (10.6 qt)
Dry: 12.5L (13.2 qt)

Pressure Taps Available:
Line pressure

Transfer Design:
Two-Axis design, link chain assembly

Assembly Sites:
Windsor, Ontario, Canada

APPLICATIONS
Chevrolet Cavalier (MN4)
Chevrolet Malibu (MN4)
Pontiac Sunfire (MN4)
Pontiac Grand Am (MN4/MN5)
Oldsmobile Alero (MN4/MN5)
Saturn L-Series (MN4/MN5)

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2003 Changes

2003 Model Year Summary

• More Accurate Line Pressure Control Solenoid

• Sealed Pressure Switches

• Driven Sprocket Support Thrust Washer Improved

FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES

MORE ACCURATE LINE PRESSURE CONTROL SOLENOID

A solenoid is an electro-magnetically-operated valve. In this transaxle it controls fluid pressure to the clutches, affecting the smoothness of the shifts. This solenoid was replaced by a unit manufactured with more precision and the result is less variation in line pressure and more accurate operation.

SEALED PRESSURE SWITCHES

There are six pressure switches and a temperature sensor on a manifold attached to the valve body inside the transaxle. These switches signal the control module when various shifting actions occur. The switches have been partially sealed to reduce the possibility of contaminants in the fluid impairing their operation. This results in greater reliability of operation.

DRIVEN SPROCKET SUPPORT THRUST WASHER IMPROVED

A thrust washer is a flat, round bearing that axially locates the driven sprocket gear against the driven sprocket support of the transaxle. Tabs were added to the washer so that it will be positively located on the driven sprocket support during assembly. This results in easier assembly. The material was also revised to a high temperature nylon to increase its toughness.

LOW MAINTENANCE

The transaxles use DEXRON III fluid, and are “fill-for-life”, with no maintenance scheduled for normal operation.

OVERVIEW

The Hydra-Matic 4T40-E and Hydra-Matic 4T45-E are electronically controlled four-speed transaxles with low noise, high durability and smooth shifting resulting from sophisticated electronic controls integrating operation with the engine. The 4T45-E is a variant of the 4T40-E, added in 1999 to handle higher engine torque. Most of the robust components developed for the 4T45-E are now incorporated in both transaxles. The 4T45-E, however, still features a wider chain for greater torque handling capability, which is the defining difference between the two transaxles. Since 1999 continual development has improved durability and reliability of operation.

The 4T40-E received GM’s proprietary Electronic Controlled Capacity Clutch in 1997 on 3.1-liter V-6 applications, and in 1998 all 4T40-E transaxles, and in 1999, all 4T45-E transaxles received the ECCC technology. ECCC allows a very small degree of controlled slip in the torque converter lockup clutch to dampen drivetrain pulses and contribute to smooth delivery of power.

Both transaxles' low-noise operation is a result of the high helix angle gears, an enclosed bell housing, and the random-pattern chain. Mass has been reduced through optimized case design and use of lightweight materials.