I had a 94 Firebird that was my daily driver, transmission was working good no slipping but one day I stopped at a red light and when it turned green car felt heavy, can't really describe if it started on 3rd or 2 gears trying to go at the same time but it felt really weird and also moved a little forward if I revved the engine on neutral even starting the car it moved a little, I bought another transmission put my 94 valve body on it and the car ran perfect and sold it that way

But now that transmission that I pulled out I need it for another 94 Fbody project
I've never worked on a transmission before but did a lot of reading and had the courage to get into the project, I disassembled it front top to bottom and still i can't find the original problem, it had very little no clutch mist

Only thing so far is that the forward sprag overheated a lot and one of the metal covers kinda welded to the gear assembly (Pictures attached) it rotated smoothly by hand and locked the other way no sounds or anything felt smooth at least by hand

Do you guys think that could be the original problem?

At the time i didn't test going thru all of the gears manually but it did had reverse can't really remember much but all i do remember is that it felt heavy and moved the car forward on neutral

Any inputs would be really appreciated

 

The OP first emailed me directly and I suggested he post a new thread as I don't have the experience to answer this.