is there are bearing inside the end of the diff where the driveshaft bolts to?

im still getting a vibration from the rear end from 30mph+

i just replaced my old driveshaft with a new one, and the vibration is still there (the old driveshaft had binding U-joints front and rear).

i don't know what else to do, besides dropping the whole rear end, and rebuilding everything. i don't really want to throw a ton of money at a problem im not sure how to fix.

 

maybe lift the car up and put it in gear and watch to see if anything shakes. maybe it could be a cv axle.

 

jack the car up and spin the wheels while in neutral feel for anything binding.

 

when i was done changing the driveshaft today, i started the car, and put it in 1st gear, brought the car to about 35mph, and no vibration or anything....so i thought maybe it was just the binding U-joints.

with the car shut off, i have spun the wheels both ways in neutral, didn't feel anything strange, and the wheels bearings are good.

after cleaning up, i took the car for a spin around the neighborhood, and right when i get to 30mph the vibration is back.

i don't know what else to do.

the next thing i am going to replace is the motor mounts, trans mount's, and diff mounts...i know they are all weak, and crappy...so maybe that's the problem?

 

Have you replaces the rear steering (DTSS?) bushings with solid ones? One of mine was blown when I bought my TII. Though I don't recall vibrations above a certain speed, the back end of the car felt like it was jigging six inches to the side each time I shifted gears while driving.

Also, is your front diff mount in good shape?

 

your rear tires are balanced?

 

Allright, it may be the wheel bearings. When I make hard right turns above 30mph, the vibration stops.

 

If it sounds like Rumble Strips then its a wheel bearing.. Not sure what type of Vibration it is.. But you should beable to hear it also!

 

shouldnt he be able to lift the rear wheels and try shaking the wheel by hand to see if it wobbles? that should tell if a wheel bearing is bad right?

 

i grabbed the wheel's at 3 and 9 o'clock and shook, and again at 12, and 6 o'clock, and shook....there is a little bit of play, but barely anything at all.

would the driver side rear bearing be bad since making a hard right above 30mph makes the vibration go away?

it sounds like small, fast rumble strips, and i can hear it pretty well.

looks like ill be spending next weekend doing rear wheel bearings on both sides. i was looking forward to buying some fun stuff for my FC for once, but Maintenance isnt a bad purchase.

 

this is kind of odd. I actually have the exact same problem as of yesteday....

 

mines doing the same thing, vibs around 45mph, car jigs to the right when hard in 2second gear

anybody figured this out, or do they have a break down date on themLOL

 

Check the rear diff mount.

 

Check the way that the Driveshaft Bolts onto the Diff Flange.
there is a lip that the driveshaft sits IN/ON,,and if it isn't sitting flush,then when you bolt it up,.it will not be Flush.Therefore you will get an imbalance.
Instead of Tightening the bolts around the "clock" (spinning the drivesahaft and tightening each bolt as you see it) Try tightening on opposite corners.It may help alleviate the problrm.
But My guess is a bad Sitting driveshaft or a bad U joint..again,
the Diff mount..not so much.

 

I'm not sure if bad wheel bearings can cause a vibration, they normally cause humming noise and I would think if its bad enough to cause a vibration the play on the wheel would be noticeable. In your case it would be the passenger side bearing thats bad if the noise goes away when you take a right turn, since that takes takes the load off that bearing. I would jack the car up from the rear and have someone put it in gear and accelerate while I observe any weird movement in the drivetrain.

 

Interesting...

I just had my diff rebuilt, and the trans shop erased the marks I had made on the flange that bolts to the diff. I get a ridiculous amount of vibration above 30mph.

I assumed that this was because the drive shaft wasn't properly aligned w/ its previous position in reference to the diff, but I also replaced my front diff mount (competition) and rear diff mounts (MMR) . I would expect to get some increased vibration from the mounts, but not THAT much

 

if anyone comes up with a fix on these vibrations ,, be sure to post it, it would make for some happy guys!

 

i ended up replacing both wheel bearings, they were the problem.