Bad Vibration at 70+ MPH

onefstsnake

New Member
Nov 25, 2005
792
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Northern VA
Well Ive searched and have found alot of great info but nothing to solve my vibration problem.

Car is a 93 Coupe. TKO 600 trans, FMS Aluminum DS, Auburn Pro Locker, 31 Spline axles, and FMS 4.10 gears.

Vibration happens at 70mph and continues at higher speed but doesnt get worse.
No vibration under 70mph. I can put the trans into neutral and the vibration is still there. The vibration is so bad I cant see out of the rear view mirror.

Ive tried 2 sets of wheels/tires, U Joints have no play, and the wear patern on the gears looks good.

I also have a gear whine under deceleration.

Could a bad bearing in the rear cause a vibration like this?

Also how much play should there be between the splines of the axle and the internal splines in the carrier?

Any help would be awesome!

Thanks,
Ken
 
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My car is kinda doing the same thing. I heard it could be the drive shaft is out 180deg., but have not tried it yet. Have you? I checked my wheels for play when jacked up and i do have a little play in steering rack boot. does yours?
 
I havent tried rotating the driveshaft 180* but with an aftermarket DS I wouldnt think this would do anything since the DS is balanced off the car.

Also I havent checked the steering rack, but I dont get much vibration in the wheel.
 
Considering it still happens with the trans in neutral, that narrows it down to the driveshaft and back, possibly the tire balancing too.

The DS comes out easy, take it and have it checked out.
I'd also have your rear tires balanced, make sure they are doing more than just a static balance, good rims require a dynamic balancing, trust me, it makes a difference.


Brytell, your's sounds like wheel balancing and alignment, they are usually the only things that makes the steering wheel shake.
 
Ive tried two different sets of wheels/tires and still get the exact same vibration.

And the DS is a FMS Aluminum piece w/ good u joints. I might try just flipping the DS around and see if it helps but since its not a factory DS it wont be balanced to the car...
 
jack the car up and let the wheels spin slowly in first, that would be the easiest way to check. it is more than likely either the crush sleave inside the rear end that preloads the bearings for the pinion, the driveshaft is tweeked (i had the fms aluminum driveshaft get bent while stabbing a motor because it was not disconnected and it started doing exactly what your describing) or one of your axles are bent. hope it helps.
 
well the only other thing I can think of besides these if a harmonic balancer. or tie-rods. and tighting a lose strut. Make sure the Drive shaft bolts are all the way in. slightest out and you will have bad vibration.
 
I get basically the same thing you're talking about and everything was fine before I swapped to the TKO600. only thing I can really think of it being is the driveshaft since I had to change the transmission yoke to match the TKO output. I have been thinkin of just trying to flip the yoke 180* and see what happens. I would try the same thing if I were you and then you can at least rule that out
 
I'm also struggling with a vibration from 65 up. Thought it was the pinion angle so I changed that and it helped a bit.

But now I've got a really bad vibration above 4000 RPM in all gears under acceleration. I hate it.

I changed my u-joints, but need to drop my drive shaft and go have the balanced checked to rule that out. I suspect it might be my clutch/pressure plate, but that's just a wild guess. The clutch needs changing anyway because it slips when I get on it and shift hard into 3rd.
 
I'm also struggling with a vibration from 65 up. Thought it was the pinion angle so I changed that and it helped a bit.

But now I've got a really bad vibration above 4000 RPM in all gears under acceleration. I hate it.

If you are sitting still with the clutch in does it do this? If so, definitely check the harmonic balancer on the crank pulley. Mine does this and I have new one on the way.