legacycentral bbs

I have had a vibration issue with my car for quite some time and the driveshaft has had the u-joints replaced twice and been on the balance machine 3 times. It checks out ok. They even put the car up on the rack and ran it to check the cv shafts, although they were obviously at a different angle than with the car on the ground. The vibration is only apparent when in 4th gear and not all the time. I was wondering if there was anything in the tranny that could replicate a u-joint type of vibration?

Jeff

did the carrier bearing check out ok?
is it a 2 piece shaft and if so was it bolted together in the same orientation that it was balanced in?

The driveshaft runs at about four times the speed of axles so it should be simple to tell which one of them it is.

Is it an auto or manual. Have you tried putting a stethoscope or screwdriver to the box while it's on the hoist and the vibration is happening?

Is the vibration effected by load?

It has been a while since I messed with it so I am going from memory on some things. The car is a 5 spd. and there is a carrier bearing that you can't get to along with a cv joint. I believe the auto cars just have a carrier bearing and a u-joint. I really don't remember if the shaft comes apart or not. When the car was on the lift we never got the vibration to appear. Everything checked out, but like I said the shafts were at a different angle than when the car is on the ground. I am parting out a 93 ss and I am going to swap the cv shafts into mine to see what that accomplishes. I really don't understand why it is only apparent when in 4th gear and then not all the time and it does seem to get worse when you are out of the throttle. I do need to go through the tranny and rebuild it for several reasons. I just was wondering if I should push it more to the top of the list if there is something in the tranny that could be causing that type of vibration.

Jeff

How's your tranny mount?

I put the sti tranny mount in.