Strange issue

[MarksmanAkula]

Alright so I've got a weird issue going on with my Jeep. I'm getting a vibration in the rear end, but only at 35-45MPH, Only under load from the engine (If you let off the gas it stops) and only to one wheel in the rear end. Passengers side rear wheel, No others. Sounds like running over a rumble strip on the highway.

I'm completely stumped on what this could be, as I've heard it can be a number of things.

Any help is appreciated, really want my jeep back to normal driving!

 

[lfhoward]

Just checking, is this an ABS noise, or something else like something that is vibrating and resonating at that speed? Can you feel the vibration or only hear it?

Other things I would check to rule out:
- Lug nuts on that wheel tight?
- Brake dust shield on that wheel rusty/loose?
- Heat shield above muffler rusty/loose?
- Exhaust hangers broken at all?

Anyhow, I got to thinking about exhaust-related noises because the exhaust pipe goes right behind the passengers rear wheel. The exhaust could vibrate under load if something there is loose, and make it sound like it could be coming from the wheel.

 

[LibertyTC]

& then there is the mechanical side, of rumble in the jungle...
Are the wheel balance weights still on the rims? Have balance checked at a tire shop.
Inspect rear wheel bearing/hub for any upward or sideways play with tire off the ground...
Then Rear diff, pull the cover, any particulate matter/ inspect for any damaged gears etc.
Next would be driveshaft/ u joints etc...

 

[MarksmanAkula]

& then there is the mechanical side, of rumble in the jungle...
Are the wheel balance weights still on the rims? Have balance checked at a tire shop.
Inspect rear wheel bearing/hub for any upward or sideways play with tire off the ground...
Then Rear diff, pull the cover, any particulate matter/ inspect for any damaged gears etc.
Next would be driveshaft/ u joints etc...

Driveshaft U-joints have been replaced, driveshaft has not been balanced, tires are fairly new (Will rebalance them again) have not checked for axle bearing play, and had the diff open a few months ago, didn't seem out of the ordinary.

As far as I can remember the previous owner stated that this was an issue, but its driving me crazy that I cant figure out what it is.

 

[MarksmanAkula]

Just checking, is this an ABS noise, or something else like something that is vibrating and resonating at that speed? Can you feel the vibration or only hear it?

Other things I would check to rule out:
- Lug nuts on that wheel tight?
- Brake dust shield on that wheel rusty/loose?
- Heat shield above muffler rusty/loose?
- Exhaust hangers broken at all?

Anyhow, I got to thinking about exhaust-related noises because the exhaust pipe goes right behind the passengers rear wheel. The exhaust could vibrate under load if something there is loose, and make it sound like it could be coming from the wheel.

Exhaust is tight to the body, and is brand new as well. Part of me is thinking its the parking brake coming partially engaged, as it doesn't really work. Last time I did brakes I made a note to myself to change it out, but I never did. I think its engaging on the disc while driving and catching/slipping.

It is something you can feel yes. Not throughout the whole car, but more specifically in the rear. It is localized not widespread.

 

[Big Al]

Put the rear end up on jack stands and bring it up to the speed that you normally feel the problem is. You might have to buy a mechanics stethascope to pin point the area. Be careful, lots of hazards if you want to try this.

 

[JeepJeepster]

Rotated wheels to see if it moves?

 

[MarksmanAkula]

Rotated wheels to see if it moves?

That's my next move. Going to put front tires on the back and the back to the front. If it still persists, then my next thing will be to replace my axle bearings and replace the parking brake shoes and hardware.

 

[JeepJeepster]

If the sound gets worse when you lightly pull up on the parking brake then you know its something to do with that... Im not sure wheel bearings could cause a vibration and not make just horrible sounds at all speeds.

 

[MarksmanAkula]

If the sound gets worse when you lightly pull up on the parking brake then you know its something to do with that... Im not sure wheel bearings could cause a vibration and not make just horrible sounds at all speeds.

Last time I had the brakes off I dont even remember the parking brake functioning. Or barely functioned for that matter.

And I hear no bearing noise either, jeeps all quiet until the vibration decides to happen.
At this point I'm grasping at straws trying to get this fixed.

 

[65Corvair]

I have had a similar rumble noise from the rear of my Jeep too. Mine is more from 40-45 mph only under acceleration. It almost seems like the frequency makes the whole chassis vibrate/resonate.
Once I greased my u-joints the problem went away. You said your u-joints are new, are they free to move with the drive shaft removed from the Jeep?
Is your Jeep lifted or at stock height?
I don’t know if this is what is wrong for you, but this is what “fixed” mine.

 

[MarksmanAkula]

I have had a similar rumble noise from the rear of my Jeep too. Mine is more from 40-45 mph only under acceleration. It almost seems like the frequency makes the whole chassis vibrate/resonate.
Once I greased my u-joints the problem went away. You said your u-joints are new, are they free to move with the drive shaft removed from the Jeep?
Is your Jeep lifted or at stock height?
I don’t know if this is what is wrong for you, but this is what “fixed mine?

Yes, U joints are brand new. Had the shaft out this past weekend and actually got pinched twice because both ends swing so free. They're tight, but are free moving. (EDIT : They are non-greaseable joints.)

Also at stock height, or as tomm would say, sagged because I haven't replaced the springs/shocks yet.

If any of my other fixes dont work I may take the driveshaft to get balanced or just replace it all together.

 

[Shane Giggie]

I didn't have any noises in my 06 till I changed the muffler and tail pipe now I get a rattle/vibration at certain rpm and speed. Mechanic said it was a default in the new muffler wasn't welded correctly, cheap Napa junk.

 

[MarksmanAkula]

Got an update on this issue (Not sure if it solves it yet)

Took rear driveshaft to be balanced, and got a call saying one of the weld yokes was bored out, or too large to hold the U-Joint cap in place causing it to wiggle.

Shop is going to replace the weld-end, 2 new u-joints, and balance.

Will report back Monday if this fixes the issue or not.

 

[MarksmanAkula]

Just a endweek update on this - Jeep is still in the garage on stands.

Axle bearings are being replaced, along with E-brake hardware (Because one side was missing, I mean hardware, pads and all.)

I get the driveshaft back Monday afternoon.

 

[Big Al]

Whoa,
Missing parts, send us a few pictures of the rebuild. My rear end is growling too.
Need to do it soon too.

 

[MarksmanAkula]

Whoa,
Missing parts, send us a few pictures of the rebuild. My rear end is growling too.
Need to do it soon too.

Growling from where? One side or the other or is the pinion gears making noise?

 

[Big Al]

Growling from where? One side or the other or is the pinion gears making noise?

My spider gears and side gears are shot.

 

[MarksmanAkula]

Just another bump to this thread.

Got the shaft back yesterday and it looks brand new. New weld yoke, rotated shaft, 2 new greaseable U-joints, etc.

Will get the liberty back together tonight and report back. Sadly no 4WD system due to a bused shifter bushing.

 

[MarksmanAkula]

Just another bump to this thread.

Got the shaft back yesterday and it looks brand new. New weld yoke, rotated shaft, 2 new greaseable U-joints, etc.

Will get the liberty back together tonight and report back. Sadly no 4WD system due to a bused shifter bushing.

Alright final bump here. Jeep still shakes.

sorry I couldn’t find a solution to the mysterious shake that some of these vehicles have, and that no ones ever found the “cure” for.