| Manufacturer | Chrysler Corporation |
|---|---|
| Also called | A604 42LE/A606 40TES |
| Production | 1989-1992 |
| Predecessor | A670 |
| Class | 4-speed automatic |
| Related | 41TE, 42RLE, 41TES |
The Ultradrive is a 4-speed automatic transmission from Chrysler Corporation. It was produced starting in 1989. It was originally paired primarily with the Chrysler 3.3 engine in vehicles with transverse engines. The Ultradrive was produced at Kokomo Transmission in Kokomo, Indiana, a plant which still makes front wheel drive Chrysler automatic transmissions.
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The Ultradrive was a significant technological advancement in transmission operation, one of the first electronically controlled automatics. It pioneered many now-common features such as adaptive shifting, wherein the Electronic control unit optimizes shifting based on the driving style of the operator. It earned a reputation for being unreliable. While the Ultradrive transmission had numerous issues, reportedly due to being rushed into production, a common problem was not necessarily caused by a design flaw, but by poor labelling: both owner's manuals and transmission fluid dipsticks advocated the use of Dexron transmission fluid in the event the required fluid was not available[1]. The transmissions were designed to use a special fluid (Type 7176, also known as ATF+) and many owners reported failures from the use of Dexron, as well as temporary issues which were resolved when the proper fluid was added [2].
There may also have been mistaken impressions of failure due to the "limp home" feature. When the computer sensed a problem, such as a sensor giving an inappropriate reading, a code would be stored in the car's computer and the transmission would be kept to the first two gears, so that owners could drive but would still return to a dealer for repairs. This could have caused perceptions of failure and premature replacement[3].
The torque converter measured 9.5 in (24 cm) 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. There were no bands or mechanical holding devices; ratios were supplied by five different clutch packs. This allowed the transmission to be lightweight and to use fewer moving parts than the three speed it replaced.[4]
The 41TE transmission which directly replaced the Ultradrive had a similar design and could be considered an evolutionary change, but it included different valve bodies, solenoid packs, sensors, and other components to increase reliability. This line was also given a flash-programmable TCM and, in 2006, a variable line pressure hydraulic system was phased in, which boosted performance and longevity.[5].
Mitsubishi's Sportronic transmission was a modified version of the 41TE.
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 and 3.8 L V6s and the fourth type for the 2.0 and 2.4 L engines.
The most common problems with A604 transmissions are poor shifting quality and sudden locks into second gear ("limp-home" mode) caused by the transmission computer detecting problems with sensor data. Nine design changes were made in an attempt to fix clutch failure, and four were directed to excessive shifting on hills.
After 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.
Applications:
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:
Since 2003 (2004 model year), the 41TE was replaced by a similar but cheaper and lighter 40TE transmissions in cars equipped with inline-four naturally aspirated engines.
Applications:
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:
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 transmission. The case has also been modified. This transmission is still in production for several models.
Applications:
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:
The 62TE is a six-speed derivative of the 41TE first introduced on 2007 Chrysler Sebring models fitted with the 3.5 L EGJ V6. Applications also include the Pacifica crossover (4.0 L), the RT Platform minivans (3.8 L & 4.0 L V6; also 2.8 L Diesel for Europe), and the Dodge Journey (3.5 L).
Applications: