External Transmission cooler?

[V8 00USH]

Originally Posted by bcredliner

IMO a cooler is masking the core problem in normal driving circumstances.

Well if that's the case it's doing a very good job of masking it for 20,000 miles!

Originally Posted by bcredliner

The transmission cooling is designed for the optimum operating temperature range for the transmission. If the temperature is varying beyond specifications there is something not working properly in the existing components.....

.... If I recall correctly the max temp. spec. for the 5HP24 is 200 degrees. If the transmission temp is above that during normal driving something is not working properly.

This is were we could really do with a sample of temperatures to see if my findings are normal or not. 200 degrees F is 93 degrees C which is 2 degrees under where mine started acting up.

Originally Posted by bcredliner

I notice you were towing. Was that the case prior to the cooler?

Yes, I bought it primarily as a tow vehicle - I just enjoyed driving it that much I ended up using it more and more as a daily when I fancied a change from my 330d.

Originally Posted by bcredliner

Transmission symptoms can be misleading. IMO if ones transmission is not operating properly it is time to get a diagnosis from a well recommended transmission shop familiar with your model transmission.

As I mentioned further up the posts - it would probably have been a transmission out job anyway as I'd exhausted all other options. I've got a spare box with knackered clutch packs if it ever came to it but I'd rather I got as much mileage out of this box as possible if it is on it's way out.

Originally Posted by StephenVA

Question: Is this a case of needing the latest trans software and Transmission adaptive memory refresh after a fluid change that created a new dynamics with the normal shift operations?

All done when it went in for a torque convertor under warranty.