Transmission issues summary

[JCL]

Originally Posted by bcredliner

Can anyone answer the question of which transmissions are problematic, which are prone to what problems?

I don't think there is any consensus on that question. All of the automatics in the X5 (GM, ZF, 5 speed, 6 speed, 4.6 variant) have had some amount of failures. Those failures don't appear to have been related to wear out due to overheating or overloading most of the time, but rather sensors, actuators, and random failures that are not precipitated by distance or load. The exceptions to that would be the 4.6 torque converters, and the early diesels (the GM trans was under-spec'd in the first diesels). It is really difficult to engineer in reliability after the product has been designed and manufactured. It involves a long development and testing process; neither is practical for an owner. You can't improve base reliability by doing things that aren't related to the common failure modes, ie replacing the fluid. That particular one usually won't hurt, but it isn't likely to help.

I don't think it is practical to swap in a different automatic. You would give up the electronic integration most likely. You could swap in a manual, but that seems like a lot of work.

Personally, I would just work to reduce the risk to the minimum possible, within the constraints presented. That is why I recommend ZF fluid and OE filters, for example. They aren't necessarily that much better, but they are lower risk.