what could cause this vibration

[86turbo]

I am having vibration in my 85 coupe. I was on the freeway earlier nd I punched it in third and 4th gear and I got vibes getting worse as rpm increases. I shifted into 5th at the same mph and it instantly disappeared. This makes me think it is NOT a mph issue therefore that would eliminate my driveshaft, wheels, tires, etc. I get a slight vibration in higher rpm in first and second gear but nothing like 3rd and 4th.

btw, 5.0 with h/c/i and t5

Any ideas?

Drew

 

[mc0311grunt]

tailshaft? Mounts? I would still check out the u joints.

 

[GTOreturns]

Higher RPM's? Drive shaft? Tranny mount?

 

[ID89GT]

My guess is either motor or tranny mounts. Possible drive shaft too.

 

[TenorPlayinGuy]

Worst case would be the bearings in the transmission, since 5th gear is on its own. That makes sense since you get the vibration in the other gears.

 

[86turbo]

I jacked up the car today by the diff and ran it through 1st and 2nd. It's apparent that there is a viration occuring somewhere and I have pretty much ruled out it being a mph issue. It's def rpm related. Hope it's not my clutch!!