Last night at the track I hurt something in my tranny. I'm not sure what it is and figured if I explained what it is doing I can get some responses.

First of the tranny has like 10k on it max since the rebuild. It goes into all the gears but when I put it in 4th it doesn't always want to let me shift into the next gear. Feels like the shifter is just stuck in place when this happens. If i try to move it and have the clutch pedal on the floor then it makes some grinding noises. Think I might have killed a shift fork or something?
Car has the stock hurst shifter dont think it has stops.

Also how hard is it to rebuild a t-5? I'm considering doing one myself.
Thanks