Differential problem?

[VillasenorSteal]

So heres a little background. My car was originally a atx and now its a mtx. A week ago or so when i was driving to school my car starting messing up. It felt as if my tranny was destroyed. Then my car completely locked, so i couldn't move in any gear as if the brakes were engaged.

So i tow it home and take off the calipers, brakers, rotors. After removing the calipar and rotor from one side my axles were still unmovable. So then i start on the other side. One of the calipars was missing a bolt so it was resting on the hub. I thought this was the source of my car not moving. I could freely rotate my axles at this point and everything. There were no leaks and my oil level was fine.

I drove my car for thirty minutes and decide it is free of problems. So the next day i drive it for about 10 min to brake masters to get some studs. They tell me they can't replace my studs so then a mechanic gets in my car and tries to reverse. I see he is having difficulty and barely manages to get it to a parking space.

By the time i get to drive it, it will only move three feet back and forwards and then it locks.

1) Do you think brake masters might of put something on back wrong? which i doubt
2) its my differential
3) has something to do with the atx to mtx swap
4) something else?

I would really appreciate some help guys.

 

[pj91gsx]

The gears in your rear diff are different for manual and transmission. You differential or you transmission is messed up most likely. did you change you diff out with the transmission?