Hello All! Basically the car is fine until around 70 mph when at that point and any speed higher it has a vibration but the weird thing is it stops as soon as you are off the gas. You could be doing 75-80 with a pretty good vibration throughout the car but as soon as you are off power the shaking stops. I have had this for a little while and am really having trouble finding the cause for the vibration. I have replaced the guibo/flex disc, center support bearing, and just had all the wheels repaired and rebalanced. Please help this is driving me MAD!!!
I have recently replaced the entire front suspension and transmission mounts. Could it possibly be rear trailing arm bushings or could the drive shaft become unbalanced over time?
the drive shaft def could become unbalanced over time, but i don't see it happening that sudden unless you did some work and dropped it or hit it hard enough.
"Entire front suspension" means different things to different people. To me, that's strut inserts, upper strut bearings, all steering joints, and all control arms. Is that what it means to you?
What car? Year, make, model? You've been a member since 1970 and this is your second post? Welcome! When trans mounts were replaced was the driveshaft marked for position? Installation in other than original alignment (90 or 180 degree rotation) may be causing an out-of-balance condition.
To CRKrieger: Yes all that and shocks, every front suspension component but the steering rack. To dogsbark26: 1997 BMW 328i 147000 miles. I did have the drive shaft apart to replace the center support bearing but I was religious about my marks and getting it back together just as it came apart. It has never been dropped and it had the vibration before the drive shaft was ever apart and I am getting tired of throwing parts at the car. I had it up on a lift today and as best as I could find it sounds/feels like it is coming from the diff. My buddy was saying maybe input shaft bearing or something like that. I was thinking of draining the diff to see how many chunks come out if any (hopefully not).
The car shakes or the steering wheel shakes? If the steering wheel, check front tire balance. If the whole car, check rear tire balance. Also check for any obviously damaged parts/bushings in the rear end or signs that one tire is wearing oddly. I doubt it is the diff. That would be one of the least likely suspects.
I would drop the drive shaft and check the rear joint. The fail alot and will have you chaseing your tail trying to find the vibration. When you drop it down, if the joint feels notchy or has alot of side to side play, thats your problem right there. Just replaced one on an 86 M6 at the shop.
You mentioned that it stops as soon as you're off the gas, So I would think it has to be more in the motor mount category than in a suspension or an imbalanced wheel. Had my 540 M-Sport up to 145 yesterday.....She was smooth as glass all the way up with more still left to go. Got there REAL quick too. Even after 7 years I STILL Love this car!
