Vibration from rear end

[thomcasey]

Ok, here is the issue. 5 months ago, I started to have a loud thumping from the rear under boost. I discovered the rear carrier bearing was loose. I performed the roofing caulk fix, but did not center the bearing in the carrier, so I got a constant semi-mild vibration.

I purchased a used drive-shaft and everything was good for a few months, then the thump started again (it was used after all). Then it got real bad as a constant vibration would pulsate from the rear. Sometimes it is gone completely, sometimes it gets pretty bad (bad enough to cause all my brake lights to not work, broke the filaments).WTF

I put the original drive-shaft back on, and I get the same issue. IN the mean time, I replaced both rear calipers due to what appeared to be a dragging issue, this also didn't help.

So, my symptoms are now:

1. Pulsating vibration from rear end
2. Sometimes vibration is completely gone
3. Brand new rims and tires
4. New Calipers and brake pads in rear
5. Car seems to drag in reverse, comes to a stop on its own easily
6. No wobble in rear wheel bearings
7. Rearend is a 4-bolt, no leaks, fresh full-synth 5 months ago.

I am looking to check into another good drive-shaft, and disconnecting the rear axles/drive-shaft to see if the drag is in the rear-end or in the wheel bearings.

Anyone have any other ideas? Transfer-case going bad?

 

[Achelea]

Okay, do NOT DISCONNECT the driveshaft and try to drive it!!!!! You'll ruin your center diff!

However, you can try pushing it with the driveshaft out to see if it slows down on it's own. If it doesn't stop on it's own, then your problem lies between your trans and your rear axle. IE Center diff, or the transfer case.

How are the pads or the Bearings on the back end?If it slows down quickly anyways, it might be dragging in the bearings

Or you could check the rear diff's fluid to see if it's burnt or if you can, pop the back plate off and take a look inside.

 

[thomcasey]

Okay, do NOT DISCONNECT the driveshaft and try to drive it!!!!! You'll ruin your center diff!

However, you can try pushing it with the driveshaft out to see if it slows down on it's own. If it doesn't stop on it's own, then your problem lies between your trans and your rear axle. IE Center diff, or the transfer case.

How are the pads or the Bearings on the back end?If it slows down quickly anyways, it might be dragging in the bearings

Or you could check the rear diff's fluid to see if it's burnt or if you can, pop the back plate off and take a look inside.

I plan on spinning each wheel individually with the axles disconnected. I hadn't planned on driving it with the drive shaft disconnected, I really don't want to roll it without it cause my driveway is an incline and I would have to muscle it back up there.

I am hoping to see if the bearings are bad. The rear diff oil is nice and clear, no leaks. I will leaf the rear-plate removal to the very end if the other steps do not produce any results towards the dragging/vibration. I fear that it could be the rear or center diff, I am just hoping for a simple bearing replacement.

 

[Achelea]

No kidding.

The only other thing I can think of is the E brake cable. *Shrugs* I hope it's a bearing for your sake.

Is it an Limited Slip rear end?

 

[thomcasey]

I believe itnis LSD. It is a 4-bolt without ABS. Also, the ebrake isn't even connected. Hoping to get it up on the air tomorrow to disconnect the rear axles

 

[thomcasey]

Well, I installed the other drive-shaft I have that I just performed a fresh "thump fix" on. But this time, I suspended it vertically to ensure the bearing was as centered as possible.

Now I only have a slight vibration that actually goes away above 70, so I know it is the carrier bearings. Now it is time to rebuild the original shaft with new carrier bearings and all new u-joints.