The other day I was driving on campus, and it was still real icy and snow on the road so I had it in 4hi. I was leaving the parking lot and drove over a speedbump with my foot still on the gas...
When the back wheels came down off the speed bump the RPM shot up. I thought I was spinning all 4 because of the ice, but the truck wasnt going nowhere. I thought maybe the shifter was not in drive all the way, and jumped back to neutral. Checked and it was still in D. Tried N, still no difference. Tried R, still like neutral. Moved down to D2, still just like neutral. Now I think I lost my tranny. So I tried putting it all the way down into D1, and "clunk" it loads up just like going from N to D. So i start driving and its staying in first, i try putting it back into OD and it upshifts twice. I stop and try reverse, works fine. Took it up on the highway and it shifted just like I expect it to... It has been fine ever since for 2 days after that...