Originally Posted by moty
its desiel 6.2 turbo and chevy chasis
Now I'm confused.
I didn't know that they used the 700R4 overdrive trans behind the 6.2 motorhome chassis. I know they did in the Chevy pickups and Suburbans, but the higher weight motorhome chassis supposedly only got the 3-speed Turbo 400. I've been wrong about many other things though.
If you don't know for sure which transmission you have, crawl under and look at the transmission oil pan. The 700R4 is pretty much square and the Turbo 400 is like a race track. Here are the GM tranny pans.
Assuming you do have the 700R4, it is unusual that it will only go into overdrive (4th) when it is hot. Usually, OD either works or it doesn't. There is no power used to engage OD but there is voltage used to engage the torque converter lockup. I wonder if it is not locking the converter, which feels like a slight shift, and it isn't an OD problem at all.
Still odd about it working when hot.