Ok you muncie guys, so here is my trouble, while elk hunting, I backed up my truck (1989 V3500 4X4, 454 tbi, muncie sm465 with 205 transfer case) and parked while I glassed the hill side. I then headed up the road a ways, I did not notice anything wrong at that time but when I got going and tried to shift into third gear, it would not go.
I then found that I had no third, fourth, or reverse, first and second still worked just fine.
I limped the truck home and got the tranny tore out and apart, everything with the exception of third gear looks brand new. Third gear is worn down a bit from being ground while still moving forward apparently, this truck was a construction rig before I purchased it. I cannot find anything that looks to have caused this, I was going to rebuild it however I don't know what needs to be replaced and I don't want to rebuild it and find that was not the problem. I have talked to several of the local mechanics and they don't seem to know what might be wrong or just don't care, Any help or suggestions would be greatly appreciated.