My father is having problems with his overdrive. At 55-60 it is shifting in and out of overdrive on flat ground. It has been to the dealer and they even replaced the whole trans and OD. It still dose the same thing. Any one have any info on this. It would help a lot. Thanks:D

try dodge-diesel.org and do a search, there are more than a few things that will cause it. the problem with mine was too much fluid. it says to check the level in netural and they mean it. mike

Is it actually shifting out of OD or is the T/C just unlocking? You can tell by the change in RPM, 50-100 RPM change is the T/C unlocking, anything more is a downshift.

There is a known issue with the T/C lockup selenoid and the T/Cs themselves going bad. Was it/were they changed with the rebuild/swap?