Was at the track today, did 2 passes and my clutch got stuck down at the end of my runs for some reason. I had to physically pull the clutch pedal up.

I did one 1/8th mile run with no problem.

Did another 1/4 mile, slammed it in 3rd as usual and it missed the gear (i believe i had it in the right spot). Anyways, after that, on the ride home it clatters and pops out of 3rd unless i forcefully hold it in place. Occasionally it pops out of 4th as well.

Why was the clutch stuck down?

I did some searching and it sounds like the slider keys are worn out to make it pop out of gear. How can i be sure of this? I am a diy kind of guy so it looks like im gonna be pulling the trans and rebuilding that. Anything else i should do at the same time? Probably gonna change the clutch.

I think it may be possible that i bent the linkage or something, is that a possiblity and how do icheck for that?