Ultradrive

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Ultradrive
Overview
Manufacturer Chrysler Corporation
Also called 41TE/A604
42LE/A606
40TE
41AE
40TES/41TES
42RLE
62TE
Production 1989-present
Body and chassis
Class 4 or 6-speed automatic
Chronology
Predecessor TorqueFlite

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.

History

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fluid was not available.[1] The transmissions were designed to use a special fluid (Type 7176, also known as ATF+3, now superseded by ATF+4) and many owners reported failures from the use of Dexron, as well as temporary issues which were resolved when the proper fluid was added.[2]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 default to second gear only, under transmission computer control, so that owners could still drive to a service location for diagonsis and/or repairs. This could have caused perceptions of failure and premature replacement.[3] A major drawback to the "second gear only limp mode" was, if second gear was the defective gear, the vehicle would not go forward at all.

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]

"Autostick" option

In some applications, a driver could select a certain gear with an extra position on the stick. This was called "Autostick" and required the driver to press on the safety button on the selector stick and then the stick could be moved to the "manual" position, where side-to-side movements towards the + and - icons made it possible to manually engage the transmission sequentially through all 4 forward speeds, but the computer kept some supervision in order to limit maximum engine RPM or prevent too low a gear for the vehicle speed. This option was advantageous in certain driving conditions, like slippery roads or mountain driving.

Technical information

There are 4 different types of units. The differences between the types are the bell housing bolt pattern and valve body assemblies.[citation needed]

A604/41TE

The 41TE is a four-speed transmission fitted on 1989 Dodge/Plymouth vehicles with the 3.0 L 6G72 V6. Applications include (but are not limited to) the Dodge Caravan/Grand Caravan, Plymouth Voyager/Grand Voyager, Dodge Shadow, Chrysler LeBaron and Chrysler Sebring (1995-1997).

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:

40TE

Since 2003 (2004 model year), the 41TE was replaced by a similar but cheaper and lighter 40TE transmissions in cars equipped with inline-four-cylinder, naturally-aspirated engines.

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 use in rear-wheel drive vehicles by removing the integral differential and transfer chain. Power flow exits the rear of the transmission. The case has also been modified. By design it has full electronic shift control with adaptive memory to learn the operator's driving habits controlled by the vehicle's Transmission Control Module (TCM). Contained within the automatic's torque converter is an Electronically Modulated Converter Clutch(EMCC) designed act as a shock absorber for harsh shifting.

Gear Ratios for the 42RLE:

  • 1st: 2.80
  • 2nd: 1.55.
  • 3rd: 1.00
  • 4th: 0.69

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 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:

Problems

Many problems with Chrysler automatic transmissions are started when the automatic transmission fluid or "ATF" is replaced or topped-up with standard, more common fluids like DEXRON or MERCON type fluids. Chrysler transmissions need to use their own fluid, designated as ATF+4 Synthetic type 9602 fluid from Chrysler, not any other or any other plus an additive. If any quantity of other type of fluid is added to the transmission, a complete drain, flush and replacement with the correct ATF+4 will be needed. When properly serviced (periodic fluid and filter changes with the required ATF+4 fluid), the transmission performs correctly.

The most common problems (shift stuck-, limp mode-, blocking problems) with the Chrysler Ultradrive 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.[6]

After pressure from the US Center for Auto Safety,[7] Consumer Reports, and others, Chrysler LLC promised[citation needed] to waive the $100 deductible in the warranty, provide loaners, and buy back any cars with Ultradrives that could not be fixed (US located cars only). Chrysler ran an unprecedented campaign to contact all American owners of cars with Ultradrives to find and fix problems.[8]

See also

References

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  6. ↑ http://www.autosafety.org/chrysler-ultradrive
  7. ↑ http://www.autosafety.org/files/CASultra_0.pdf
  8. ↑ http://www.autosafety.org/files/XLERultra.pdf
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