Clunking from rear end

Jamison C

Jamison C

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Couple nights ago I started hearing some clunking from the rear end. I haven’t had time to dig into it until my day off tomorrow, but I’m wondering if anyone knows off the top of their head what this might be. It’s not consistent with speed or road condition. The noise is just kind of random.

I rocked it back and forth last night after work and from underneath it it almost sounded like it was above the gas tank.

 
My first look would be at the rear sway bar links. See if there is any play in them.

Edit: I'd also check to make sure you have nothing rolling around in the back. Seems trivial, but some weird noises I've discovered was something clanking around in the back while driving.
 
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Check the rear sway bar

Check the spare tire

Check the u joints in rear drive shaft

Check the shocks

Check the control arms by rolling the Jeep forward in gear , not running ,and back and looking at where they mount

Be sure the seat is secure

Check the parking brake lines also

Let us know what you find
 
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AndyG said:
Check the rear sway bar

Check the spare tire

Check the u joints in rear drive shaft

Check the shocks

Check the control arms by rolling the Jeep forward in gear , not running ,and back and looking at where they mount

Be sure the seat is secure

Check the parking brake lines also

Let us know what you find
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Took me a day or two to figure out my back seat was flopping around when flipped up and the little flashlight in my console was rolling around.
 
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Check the tightness of all mounting bolts. A loose sway bar bolt or track bar bolt can not only cause noises but can quickly cause a mount point to wear (like wallowing out a mounting hole) which can quickly get expensive to fix.
 
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Thanks for all of the suggestions! I’m gonna drop the tank later to get a better visual on everything underneath the rear.

Just my luck I was telling someone not three days ago how reliable my Jeep has been 😂😭
 
The closest thing to the top of the gas tank would be the frame mount for the trackbar. I would carefully check that along with the other stuff already mentioned.

You might also check that all the bolts for the gas tank skid are there. If you lost a nut (ouch!), one of the carriage bolts could be rolling around on the cross member.
 
Well I have good news and bad news. The good news is I found the noise! Bad news is that it’s coming from inside the transfer case where the driveshaft meets the gear. Luckily everything else mentioned above is nice and tight.

When my first installer royally messed up my first gear install, there was a stupid amount of slop in the driveshaft. I’ve since regeared a second time, but my “guess” is the DS slop caused some excessive wear in the TC.

Here’s a video the Jeep shop sent me when they did my second set. Obviously that’s hard on the diff but I can’t imagine that excessive play was good on the TC either.
 
I'm not convinced that your transfer case was damaged by slop in the diff pinion bearings (that was staggeringly bad though :mad:). If you have an OE rear drive shaft setup. the slip yoke would absorb any in/out movement (like it's designed to do) and, on a SYE setup, the drive shaft would do the same. There might have been some added shock stresses but all of that drive-line stuff is designed to handle (and does handle) some pretty fearsome stresses when off-roading.

Can you get a video of the suspected point of origin for the noise? Not saying it's not your TC, just thinking there might be some other nearby culprits.
 
TJ Hunnicutt said:
I'm not convinced that your transfer case was damaged by slop in the diff pinion bearings (that was staggeringly bad though :mad:). If you have an OE rear drive shaft setup. the slip yoke would absorb any in/out movement (like it's designed to do) and, on a SYE setup, the drive shaft would do the same. There might have been some added shock stresses but all of that drive-line stuff is designed to handle (and does handle) some pretty fearsome stresses when off-roading.

Can you get a video of the suspected point of origin for the noise? Not saying it's not your TC, just thinking there might be some other nearby culprits.
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Yeah I ran out of time today, but when I have another day off I’ll have my brother roll the Jeep back and forth and I’ll get under to try and get some video of the noise.

I wasn’t so worried about the in/out as much as the back/forth, though I suspect the weaker point between the diff and the TC would be the diff gears being slammed together.

Thanks for sticking with me! I’ll update in a couple days or so.
 
@TJ Hunnicutt man do I feel like an idiot. I definitely let worry and placebo affect make me think something was there that really wasn’t.

I haven’t washed my jeep in a few weeks, so I went to the self-serve car wash and blasted the underside with the pressure washer. Guess what went away along with the dirt? The noise.

Another TJ case solved!
 
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Jamison C said:
@TJ Hunnicutt man do I feel like an idiot. I definitely let worry and placebo affect make me think something was there that really wasn’t.

I haven’t washed my jeep in a few weeks, so I went to the self-serve car wash and blasted the underside with the pressure washer. Guess what went away along with the dirt? The noise.

Another TJ case solved!
Click to expand...
AWESOME! Man, I love those $5.00 fixes!!
 
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