I have this weird noise coming from my transmission it sounds like a knocking almost like stuck lifter but when you step on the clutch it goes away
and when you release the clutch it starts again.

my car is a 82 trans am with a T-10 4 speed tranny with mechanical linkage.
I just changed the clutch about 3 weeks ago


any help would be great?

 

throw out bearing

 

I changed the throw out bearing when I did the clutch.
unless I got faulty one then that would make sense

What could it hurt if I keep running like that?

 

you could have installed it wrong, i thought i had the same prob, but its just a t56 is a nosiy trans when in neutral because the gears make noise when not under load, do a search there is tons of info bout the t.o. noise and what tells you if thats the prob or not