Chrysler motors corporation developed the A-604 41-TE 4-speed “commonly called ultradrive” in (1988) during the restructuring period in the Lee Iacocca era. The ultradrive 41-te, was the first advanced adaptive learn automatic transmission that used electronic sensors and silonoids rather than bands to shift the transmission. This transmission was in production from (1988) to (2017). The (1988/91’) units were the first revision of the A/604’. My 91’ model is under this revised version. These transmissions are very well known to fail due to wear on the 3rd underdrive clutch. There is a small snap ring between this clutch that can snap and scrape the inner liner of the transmission case. When the transmission detects an issue whether or not a physical problem or an electrical software issue the vehicle will default to the 2nd underdrive drumgear. When this occurs the vehicle will slam into said gear and then increase the line pressure in the transmission. This is the limp home condition. This system was designed to allow the vehicle to be transported to a service center. My car goes into limp home mode and will display a fault on the overhead console “Low transmission pressure”. These transmissions were in a wide range of K’ car revisions post (1989). One critical issue is that transmission shops had with these transmissions in (1988/90’) is that service bulletins reported that if trans fluid ATF+4’ is not available for use, Dextron-2’ could be used as a temporary solution. This is NOT A SOLUTION! These transmissions require ONLY ATF+4. Usage of any other fluid will cause transmission failure. I have several articles that goes into detail of the problems these transmissions have had pre (1992) which I will have at the bottom of this page. Post (1992) these transmissions had a update made to the internal snap ring on the underdrive clutch #3. As well as new clutch friction plates and guides. In pre (1990) models these cars came with a singular input driveline sensor for the TCM controller. Post (1990) they have 2’ one input one output feed. Replacement of these are recommended. Also if transmission fluid leakage around the ESP (electronic shift pack) module occurs. Failure of said unit is possible. Replacement is easy and can be done in about 2 hours. Videos and resources are available online. Lastly failure of the onboard BCM/TCM can cause a slew of issue. The best and cheapest solution is to replace the sensors and ESP. But if the transmission continues to go into limp home mode. The second best case scenario is to source a low mileage/rebuilt post (1992) 41-TE.
A D V E R T I S E M E N T S
Chrysler motors corporation developed the A-604 41-TE 4-speed “commonly called ultradrive” in (1988) during the restructuring period in the Lee Iacocca era. The ultradrive 41-te, was the first advanced adaptive learn automatic transmission that used electronic sensors and silonoids rather than bands to shift the transmission. This transmission was in production from (1988) to (2017). The (1988/91’) units were the first revision of the A/604’. My 91’ model is under this revised version. These transmissions are very well known to fail due to wear on the 3rd underdrive clutch. There is a small snap ring between this clutch that can snap and scrape the inner liner of the transmission case. When the transmission detects an issue whether or not a physical problem or an electrical software issue the vehicle will default to the 2nd underdrive drumgear. When this occurs the vehicle will slam into said gear and then increase the line pressure in the transmission. This is the limp home condition. This system was designed to allow the vehicle to be transported to a service center. My car goes into limp home mode and will display a fault on the overhead console “Low transmission pressure”. These transmissions were in a wide range of K’ car revisions post (1989). One critical issue is that transmission shops had with these transmissions in (1988/90’) is that service bulletins reported that if trans fluid ATF+4’ is not available for use, Dextron-2’ could be used as a temporary solution. This is NOT A SOLUTION! These transmissions require ONLY ATF+4. Usage of any other fluid will cause transmission failure. I have several articles that goes into detail of the problems these transmissions have had pre (1992) which I will have at the bottom of this page. Post (1992) these transmissions had a update made to the internal snap ring on the underdrive clutch #3. As well as new clutch friction plates and guides. In pre (1990) models these cars came with a singular input driveline sensor for the TCM controller. Post (1990) they have 2’ one input one output feed. Replacement of these are recommended. Also if transmission fluid leakage around the ESP (electronic shift pack) module occurs. Failure of said unit is possible. Replacement is easy and can be done in about 2 hours. Videos and resources are available online. Lastly failure of the onboard BCM/TCM can cause a slew of issue. The best and cheapest solution is to replace the sensors and ESP. But if the transmission continues to go into limp home mode. The second best case scenario is to source a low mileage/rebuilt post (1992) 41-TE.
Resource links..
https://youtu.be/HAZWlMj18V0?feature=shared
https://www.motales.com/engines/transmissions/ultradrives.php?fbclid=IwAR1IM4lEqaulUZ8vmOEy4IHdbGZsy397pRNFKHp1fn94SquPqRvyDhXwskU_aem_AZOxZvkWJ1dRWnj9tUin6_PgbqEPlQaZDZgxarPvsOP1FmhXSir2ZWRwhWYIqOvjh-c&mibextid=Zxz2cZ
https://www.thetruthaboutcars.com/2022/04/abandoned-history-the-chrysler-ultradrive-transmission-part-i/
Edits to this document will be made of more helpful information becomes available. Thanks for reading. Joseph
- Joseph L., Bentonville, AR, US