Rear end noise

So a few weeks ago I'm driving for about 10-15 mins and started to get a knocking/thump coming from the rear end. Sounded like rear passenger. It seemed rotational, and had a "one and two and..." rhythm to it. I pulled over and checked out, nothing seemed wrong. Less than a mile down the road the noise stopped and hadn't recurred since, until today.

My wife was driving home and about 10 minutes in she calls me saying she had to pull over because the jeep is making a weird noise. So I came and got her and drove it home, which was about another 10 mins. After about 5 minutes it started making a thumping noise, but less of a knock and more of a rubbing/squeaking from the rear passenger side. Lasted maybe 1/4 to 1/2 mile and stopped completely.

Tires were just rotated, pressure is good, rear diff oil was changed less than 5,000 miles ago. Rear u-joint was done 25,000 miles ago. Rear lower control arms were changed out from the last recall a couple years ago. Thinking maybe wheel bearings, worn bushings or something with the tri-link. Any thoughts or ideas to help me come up with a solid diagnosis?

Does it speed up with the speed of the KJ or is it more of a normal pattern no matter the speed
Does it do it at say 45-50 all of the time or at any speed ?
If rear tri link "most times" you will have like a thunk or pop when taking off or sometimes slowing down

The sound definitely changes depending on speed. Sound gets faster as I press on the gas and slows when off the gas. But it doesn't start up around a specific speed. Comes and goes pretty randomly. I will be driving say 40mph and it will start up...I can slow to a stop and speed up again and the sound will persist. Then, usually a mile or less down the road it stops and may not return for weeks.

Also...now that I'm thinking about it, maybe rear brakes are a possibility too. When it happened the first time I had just slowed down to turn onto another street and was accelerating again. Maybe a sticking brake caliper?

hectikart said:

Also...now that I'm thinking about it, maybe rear brakes are a possibility too. When it happened the first time I had just slowed down to turn onto another street and was accelerating again. Maybe a sticking brake caliper?

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How about the parking brake pads?

I had one that was catching on the drum intermittently and would make the weirdest noises. Finally it 'caught' the drum when I was on the highway at 65mph and it self-destructed.

Pull the passenger side drum and see what your parking brake looks like.

Bob

Parking brake pads were definitely part of the problem. Took the rear brakes apart and on the drivers side the parking brake pad came off in pieces...on the passenger side it was just missing all together. Did new rotors, pads and parking brake shoes in the back and it definitely seems to have helped. Also checked out the rest of the rear end and everything seems to be moving really well.

While I was in the process of figuring out the rear end issue I also started misfiring. Coil pack #4, easy fix. I had to do #5 about a year ago, so I just went through and replaced all of the coil packs.

Everything ran great with the new brakes for about a mile and now it seems like we have a new problem. The jeep will start shaking badly while I'm going down the road. It comes and goes pretty inconsistently. Almost feels like a wheel shake from tires being out of balance, but it varies in severity and really doesn't feel like a tire balance issue. It will shake and rumble worse when I let off the gas...almost like the engine is overpowering whatever it is. I don't think it's an engine problem because it idles perfectly. I also revved up to 3,000rpms in park and held it for a little bit...no shaking, everything sounded great. While I was shaking on the road going 40mph or so, I shifted into neutral to see if it would have any effect...nothing still shook. I did a test in 4hi on a dirt road...didn't seem to shake, but I also wasn't going as fast and the road was rougher, so it's possible it just wasn't noticeable. I loosened the star wheel adjuster on the e-brake as well, thinking maybe by e-brake was rubbing and causing it to shake. That may have helped, but definitely didn't solve the problem. I'm inclined to think it has something to do with the rear brakes, since it was not happening at all, and as soon as I did the brakes it started. Any thoughts as to what it could be?

Have you check the u joints?

Have you checked the lug nuts? Your nuts could have worked loose, and may need to be twisted some more!

Porkchop said:

Have you check the u joints?

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CactusJacked said:

Have you checked the lug nuts? Your nuts could have worked loose, and may need to be twisted some more!

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I'd check these first too but if not either one how bout a caliper?

I checked the u-joints, lugnuts, rear diff, calipers, wheel bearings...all look good, everything is moving smoothly with the rear-end. The rear brakes and parking brake shoes seem to have fixed the original clunking noise I was getting. Now I think I have a front end problem. Have a feeling it might be the cv's. I'm going to take a look at them tomorrow.

hectikart said:

I checked the u-joints, lugnuts, rear diff, calipers, wheel bearings...all look good, everything is moving smoothly with the rear-end. The rear brakes and parking brake shoes seem to have fixed the original clunking noise I was getting. Now I think I have a front end problem. Have a feeling it might be the cv's. I'm going to take a look at them tomorrow.

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Did you ever find out what it was? I was getting a clunk and the feeling of a boat in the rear end and when it was up on the lift I found that the Tri-Link (Rear upper control arm) Was no longer holding on so it is in the process of being replaced.