Gear box problems any sugestions?

[I_need_money]

Hello everyone this is my first post and I hope you guys can help me out, I think it is a shift fork, but since I hae never had that happen before I dont know for shure. my car will accelerate fine in 1st gear until you give it more throttle or if you try to accelerate in higher gears. it seems like it pops out of gear but the shifter doesnt come out of place and all the gears go in fine.

I want to rebuild it, but it would be great if anyone could tell me the tranny code and spline count for my transmission

My car is a 90 eclipse GSX M/T no abs, LSD rear.

I have some expience rebuilding transmissions (mostly industrial ones alot simplier haha), and work with a guy that is alot better than me at it and iswilling to help me out. I have a Mitsu shop manual and all the tools I would need. So I am pretty sure I can handle what I am getting into.

[DRW]

Check the motor mounts. If they're cracked your motor will flop around in the engine bay whenever you get on the gas. That'll tug at the shift cables and yank it out of gear. If it's an internal tranny problem the shifter would move.

[I_need_money]

Thanks alot man. I will check it out. any how I am probably going to rebuild my tranny with steel shift forks