Strange clunking sound in rear axle…not drive line slack.

[Beowulf]

Strange clunking sound in rear axle…not drive line slack.

Ok, I have a strange sound coming from the rear end that occurs after the slack in the driveline is taken up. Normally, I would attribute this to loose or damaged controls arms. I have eliminated this possibility by systematically taking each one off and reproducing the sound. Before you think I have driven around without a control arm, this reproducible with the vehicle off. All you need to do is rock the jeep fore and aft. You will hear the drive line slack and then a clunk. Having been under the jeep while someone rocks the jeep I can say that by sound and by feel it seems to be coming from right at the end of the axle. I don’t know if this could be from a bad bearing, but the wheel spins without effort or grinding, a loose retainer plate, or something else.

I am totally stumped on this one? Anyone heard of anything like this?

 

[bldeagle10]

u joint?

 

[Beowulf]

This is not in the drive shaft but in the rear axle housing near the tire. Just bearings, brakes, and retaining plates in that area.

 

[bldeagle10]

oh my mistake. axles on the xj have u-joints thought it may be the same for you.

is there any play with the wheel? jack it up and grab the sides of the tire and try and move it as if you were wiggling it off. then grab the top and bottom and do the same thing.
in that case it could be a bearing but im not sure without being there...so ill shut my mouth now

 

[donb]

I am assuming that you have a Dana 44 rear axle? I would start with jacking up the rear, and checking the wheel play as bldeagle10 suggested (with the addition of trying to push and pull the wheel in and out).

I would also recommend applying the parking brake with wheels off the ground, and see if the wheel still turns a bit. It looks like you have aftermarket shafts, and if those shafts came with threaded studs, you could have some loosening.

Even if you don’t have any movement in the wheel, I would still pull the wheel and drums. There definitely could be something going on inside with the brakes, backing plate, etc. To pull the rear axle on a Dana 44 is fairly easy, so if you don’t find anything obvious with the wheel and brakes, it wouldn’t hurt to check out the bearing.

With all that said, I’m still leaning toward loose lug-nuts and/or studs from what you’re describing.

 

[Beowulf]

Yes, these are after market Alloy USA shafts that have 50K miles and are 6 years old. The studs are pressed in, but that does not preclude the fact they could be loose. I will check that.

 

[wardrow]

Pull the diff cover off and check your ring and pinion! Sounds in the the diff can be misleading.

 

[nwoods]

Sounds silly, but I saw this once.....loose lug nuts?

 

[bat]

Find something you can stick your ear to like a piece of tubing (sprinkler pipe) and have somebody get it to clunk and you listen. I find you can pinpoint stuff using this method or look really stupid in the process.

 

[Haggis]

Pull the diff cover off and check your ring and pinion! Sounds in the the diff can be misleading.

Yep, sounds similiar to when the rear diff went out of my old Dodge. You can also try and see if there's play in the pinion by checking the pinion yoke or if the nut has loosened. Hopefully it's something else.

 

[alosix]

To add to the others:.

1.) Trackbar: both bushing + contact with gas tank skid/exhaust.

2.) Can of Ragu under the driver's seat.


Jason

 

[wjeeper]

Trackbar: both bushing + contact with gas tank skid/exhaust.

First thing that came to my mind. The rear trackbar on my YJ pops like crazy. (the bushings are shot and the bracket is half way amputated from the axle)

Funny story: This happened with a firiends TJ......his mechanic told him it was probably his dana 35 popping and it would likely be a $1000+ repair (but we knew it was just the trackbar bushing) so we built him a 31 spline, disc braked, ford 8.8 rear and swapped it in.......hope his wife doesn't ever find out we really knew what it was all along:elkgrin:

 

[Ford Prefect]

Find something you can stick your ear to like a piece of tubing (sprinkler pipe) and have somebody get it to clunk and you listen. I find you can pinpoint stuff using this method or look really stupid in the process.

I was going to suggest this as well.

Find the biggest freaking screw driver you own, and then grab it with your fist like you are going to stab down into the work bench. Put the metal end to the location that you think might have the noise, and hold your fist right up to your ear. Try it on your motor and various other engine compartment areas so you can get the idea first. It is amazing, if you have a knock in your engine this will help you be certain where it is. Once you get the hang of it, climb under and get someone to wiggle the jeep for you.

My WJ has a bit of a slip clunk as well, swapped out the front drive shaft and suddenly the sound went away, and I would swear the sound was coming from the rear end.

 

[Patman]

Had the same type of issue on a Volvo disc brake D30 once, ended up being a loose caliper bolt.

 

[Tulip]

I will agree with the rear trackbar as well. I am into rockcrawling and I see this all the time with Jeep TJ's. The front trackbar is notorious for making a clunking sound when worn, meaning that you have a bad bushing. The rear will do the same thing. Have a friend, wife, etc. rock your rig back and forth and watch the trackbar bushing on either end and see if the bolt is moving. If so, there is your clunking noise.