35-50 mph vibration

[wheelman]

I just bought a 92 SE hatch with ABS, 5-speed and a VLSD.The car is in very good shape overall with only 125,000 miles.

It has a vibration that starts around 35mph and fades at around 50mph.I feel it through the seat, not the steering wheel, it is present whether the transmission is in gear or not and when the car is acclerating, coasting and decelerating.

I think it's either the driveshaft center bearing or a u-joint, although there are no clunking, whining or grinding sounds.

I've been under the car and looked at the center bearing and tested for play in the shaft and found none. When I pushed up on the driveshaft the transmission and center bearing moved up slightly (1/16th inch or so).

The engine and transmission mounts look fine, almost new.

So, now for the question.How can I test the health of the center bearing without removing the driveshaft?Is it possible the shaft was removed, then reinstalled in a different orientation? I find it hard to believe this would cause the vibration.Is it possible the vibration is coming from worn out rotors?The fronts are pretty worn, haven't looked closely at the rears yet.

ThanksWheelman

[1KleenS13]

I would get the tires balanced. Or you could switch the location of the tires and try to isolate the vibration. Rotors could cause this, but I highly doubt it.

[gdbyyosh1to]

It is a possibility that the rotors are the culprit. I know you already checked the play in the center bearing but did you make sure that the bracket that holds the center bearing to the chassis was properly secured?

I had this same problem once and that was what caused it.

If you feel it through the seat and not the steering wheel it most likely doesn't have anything to do with the front suspension or steering, but a wheel balance never hurts...

[zach-Ka]

It sounds to me like your rear tires need to be balanced. If it was the front you would feel it predominantly in the steering wheel. if this is the issue it should cost about $7 a wheel at a shop. I hope this helped.

[240sxmech]

your rotors will only vibrate when you apply the brakes if they are warped..damn people read what he posts..when you have a vibration at a speed and then it goes away when you reach another speed it is your tires being out of balance, if it were your ujoints or center bearing or anything to do with your driveshaft or rearend it would start to vibrate and only stop if you slowed down the faster you went it would stil vibrate.....get your tires balanced and enjoy the smooth ride afterwards....

[Acecool]

I had an issue like this once, basically one of the bolts I put in my driveshaft I didnt tighten 100% and it fell off... I put it back on and it was fine ever since.

[whyteboi]

I would get the tires balanced. Or you could switch the location of the tires and try to isolate the vibration. Rotors could cause this, but I highly doubt it.

just try tires first.... if thats not it, least its a cheap place to start

[wheelman]

Thought I'd update this thread as all the others concerning this type of problem never had a resolution.

I did a full brake job on the car, replaced rotors and pads on all 4 corners, bled the system.No luck eliminating the vibration.

Swapped on a totally different set of tires and wheels, I know they're balanced and no flat spots. Still no luck eliminating the problem.

Replaced the semi-worn radius rod bushings.Still no luck.

I took another look at the motor mounts and noticed what looked like grease on the passenger side one, didn't get a good look at the driver's side. Anyway, I ordered a new set of stock mounts and will install them sometime this week, hopefully this will get rid of the problem.

BTW: While I was swapping the rear rotors and pads I noticed the rear tires are pretty hard to rotate even when the brakes are totally loose. I know the car has a VLSD which forces the drive shaft to rotate when I rotate a wheel but should it be relatively hard to turn (yes it was out of gear)? I didn't notice any points where it wanted to stick or catch (like a destroyed bearing).

[liquid_cool]

have you tryed looking at your ball joints and pillow joints or any stressed area that connects to your wheels/driveline/driveshaft...its got to be a miss alighnment..sumpin bent..or a bad joint..my mercedes used to do the same thing..it was the lower balljoints..thats all i can think of for now..hope this helps.

[djmatt79]

have you tryed looking at your ball joints and pillow joints or any stressed area that connects to your wheels/driveline/driveshaft...its got to be a miss alighnment..sumpin bent..or a bad joint..my mercedes used to do the same thing..it was the lower balljoints..thats all i can think of for now..hope this helps.

i was gonna say what liquid was gonna say....

ball joints... I had the same problem... one of my lower ball joint was loose as hell... then i got an alignment done.. and it cured the problem...

could be anything but...

check your front end and wheels...

[nightheron]

First check your wheels, if they wobble when they are spinning on the tire balancer, balancing the tires won't help. Watch out for those curbs.