Strange trans problem. What actually keeps it in gear?

[Tedskiii]

So after many hours of searching, I still havent gotten a straight answer for my problem.

So the problem is that my trans slides out of 2nd gear on my sr20det. It only does this when I do a big clutch kick, or ebrake in. If i hold the shifter in place while doing this it won't slip out. When the car is in gear the shifter feels a little sloppy, aswell as in neutral.

This recently happend after changing out my clutch, never had any problems until now. Usually when your trans im bad won't it show signs?

I'm thinking it could possible be user error from reinstalling my shifter assembly, or something could be old/worn.

I see I can get a solid shifter bushing, or even just an oem replacement. Also found I can get the shifter springs replaced.

So what actually holds/keeps the trans in gear?

I hope for the best, and it's not my trans ! Thanks in advance. Will keep this updated.