Tranny issues

[subie22]

Ok this is very strange i never had this issue, or even herd of it. I was wondering why would my car shake when i take my foot of the clutch pedal fast at idle. But when i do it slowly it doesnt make this shaking. Makes no sense to me. It started to do this when i started to adjust the pedal height. Would this have something to do with this. I recently put in a new clutch, and it was my first clutch job. But when i first started it it didnt do it. No it does. So any help would be nice.
Thanks.

 

[Lofty]

Check if the transmission mounting bolts are secure.
Can be a problem.

 

[subie22]

i should check that. But im pretty sure they are.