cluch or engine

when my freind gets to the higher rpm's there's an unplesend shaking, is that the cluch,i think it might be mis aligned, or the engine. it's sooth till about 7500 then it just starts kinda a rumbling/ shaking thing going on.

Motor mounts, tranny mount, and/or diff mount

Actually, the word for it isnt shaking its wabbleing

What year is the car?

1991 non-turbo

Well Like I mentioned in the 2nd post... Also check the U-joints.

my car usto do this when i went over 40 MPH and i decided to change the drive shaft and the problem was fixed. you may also try just changing the universal joints in the drive shaft it has 2 they look like this http://may.en.alibaba.com/offerdetail/50320850/Sell_Universal_Joints.html

thanks