Planetary gear failure

[drivfour]

What are the main causes of planetary gear failure in a transmission that has larger trans fluid cooler. I have had two back to back failures. Different transmissions-same car.
JD

[oab_au]

Originally Posted by drivfour

What are the main causes of planetary gear failure in a transmission that has larger trans fluid cooler. I have had two back to back failures. Different transmissions-same car.
JD

There could be a few causes. The main one that caused the early models to experience planetary gear failure was due to the linings that were used in the first models, flaking off pieces that blocked the ATF cooler. When this cooler flow is restricted, the flow of cool lubricating oil to the gear train reduced to overheat the gears.

Some of the gear boxes were replaced during this time, without attending to the cause of the failure, so the new box was fitted with the still restricted cooler, so another failure followed.

Harvey.