Hey guys,

I had my 1999 Ranger's 4R44E 4×4 transmission rebuilt about a year ago and have put about 10k miles on it since the rebuild. My transmission has a really peculiar issue. When you start the truck and drive away after 10 seconds or so, every once in a while it shifts hard from 1st to 2nd gear when it's doing the first upshift of the day. It will have fits and do it a couple days in a row, only to stop again. The ambient temperature seems to affect the harshness of the shift. When it's cold, it hits hard, in the summer time it's more of a bump. There is no flashing of the O/D light. It has only done it twice on later 1st-2nd upshifts, but still within the first 2-5 minutes of driving. What would cause this odd behavior? It shifts just fine once it warms up. The fluid level is fine, and the color looks like brand new fluid. The shop has been looking at it for a week under warranty, and I suspect they'll be telling me they don't see anything wrong with it again. I had them look at it in March for the same thing and they didn't have it happen.

Thanks for any ideas!

 

Did you ever figure out this issue? I'm having a similar one on a 5R55E