Ultradrive

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Ultradrive
ManufacturerChrysler Corporation
DaimlerChrysler
Also called41TE/A604
41AE/A604
42LE/A606
42RLE
40TES
41TES
62TE
Production1989-present
PredecessorA670
Class4-speed automatic
RelatedPowerFlite
ManualsService Manual

The Ultradrive is a 4-speed automatic transmission from Chrysler Corporation. It was produced from 1989 through the present and was commonly paired with the Chrysler 3.3 engine in transverse engined cars. The Ultradrive and its descendants are produced at Kokomo Transmission in Kokomo, Indiana.

History

The Ultradrive was a significant technological advancement in transmission operation, as it was one of the first electronically-controlled automatics. It pioneered many now-common features, such as adaptive shifting: the computer would optimize shifting based on the driving style of the operator. Unfortunately it earned a reputation for being unreliable, especially in Chrysler's minivans, which had high failure rates. A misprint in both owner's manuals and transmission fluid dipsticks in early models advocated the use of Dexron II transmission fluid in the event the required fluid (Type 7176, also known as ATF+3) was not available. Dexron does not provide the necessary fluid properties for proper operation of the transmission, often resulting in malfunction (commonly deferring the computer into the notorious "limp-home" mode, under which the transmission will not shift out of second gear) or complete failure of the unit. As a result, the older hydraulically-controlled 3-speed automatic was later made available on vehicles equipped with Mitsubishi's 6G72 V6 engine, which was usually paired with the Ultradrive during its first few years.

On paper, the A604 was a great innovation. When working correctly, it will shift smoothly and perfectly, thus providing a soft, comfortable ride often associated with high-end luxury cars. Also, electronic transmissions lack bands to adjust.

The torque converter measured 9.5 inches in diameter and was mounted to the flywheel by a flexible drive plate. The transaxle was cooled through an oil-to-water heat exchanger in the collector tank on the radiator, and/or a standard oil-to-air heat exchanger.

The Ultradrive has evolved dramatically over its long years of production. Countless changes, both electrical and mechanical have been made in an attempt to improve the reliability of the A604. Such changes include different valve bodies, solenoid packs, sensors, etc. One of the better improvements was the introduction of a flash-programmable TCM, which monitors the operator's driving habits, and sets up a custom shifting pattern for the driver.

The A604/41TE transmission also uses 20 fewer parts than its 3-speed siblings.

Mitsubishi's Sportronic transmission was a modified version of the 41TE.

Technical information

There are 4 different types of units. The differences between the types are the bell housing bolt pattern and valve body assemblies. The first type was used for the 2.5 L engine, second type for the 6G72 V6, third type for the 3.3 L and 3.8 L V6s and the fourth type for the 2.0 L and 2.4 L engines.

A604 to 41TE

The most common problems with A604 transmissions are poor shifting quality and sudden locks into second gear ("limp-home" mode), even during highway driving. Nine design changes were made in an attempt to fix clutch failure, and four were directed to "shift busyness", or excessive shifting on hills.

After much pressure from the Center for Auto Safety, Consumer Reports and others, Chrysler promised to waive the $100 deductible in the warranty, provide loaners, and buy back any cars with Ultradrives that could not be fixed. Chrysler ran an unprecedented campaign to contact all owners of cars with Ultradrives to find and fix problems...

A604/41TE

Applications:

41AE

The 41AE is a variant of the 41TE that was originally used for the all-wheel drive variants of the minivans, and was also used for the Chrysler Pacifica from its 2004-model-year introduction until the model was discontinued in 2008.

Applications:

A606/42LE

The 42LE was an upgraded version of the 41TE modified for longitudinal engines. It debuted in 1993 on the LH cars. It is strengthened with a reworked final drive unit, barreled axle shafts, and upgraded clutch packs. The major modification to a N-S drivetrain while maintaining front wheel drive was accomplished by adding a differential to the transmission case, which was driven by means of a transfer chain from the output shaft of the low/reverse clutch assembly at the rear of the transmission case.

Applications:

42RLE

The 42LE was modified in 2003 as the 42RLE, originally for the then-new Jeep Liberty. It is a 42LE transaxle, modified for RWD use by removing the integral differential and transfer chain. Power flow exits the rear of the now transmission. The case has also been modified. This transmission will reportedly remain in production through the end of the decade in several models. Applications:

40TES/41TES

The 40TES and 41TES are upgraded replacement versions of the 41TE, which were first introduced with the 2007 Chrysler Sebring. The 40TES is used with the 2.4 L GEMA I4 engine while the 41TES is used with the 2.7 L EER V6. The difference between the TES and TE is the TES has a shallower bell housing, and the torque converter is more compact. This was done for the revised packaging of the 2007 Sebring's engine compartment.

Applications:

62TE

The 62TE is a six-speed derivative of the 41TE first introduced with the 2007 Chrysler Sebring, and used on the 3.5 L EGJ V6. Applications also include the Pacifica (4.0L), RT Platform minivans (3.8L & 4.0L), and the Dodge Journey (3.5L).

Applications:

See also