overdrive won't shift

[Guest]

I have a 1999 expedition and when I put it in drive it barely moves. If I turn off the overdrive it works fine. 50,00 miles.
Any suggestions?
Chuck

 

[rwinch]

Don't know if this applies, but there are quite a few threads on this forum that suggest a tranny power flush helps with TC issues.

I have mine flushed every year (overkill maybe, but cheap insurance as far as I am concerned), '98 EB with 85,000...no issues.