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Prime8
06-28-2012, 02:30 PM
I have a clunking in my rear end that seems to be more pronounced in the afternoon. My car sits outside in a lot all day in the sun, whereas it sleeps in a garage all night. The clunking occurs when hitting bumps, and the larger the bump, the louder the noise. Sounds almost like something is banging into the tub...? Not sure. Any guidance would be greatly appreciated.

07rub
06-28-2012, 02:38 PM
theres not a whole lot on stuff in the back, take a look under to see if something is loose/ or broken, could be ur end links shock bottoming out a loose coil

good luck

07rub
06-28-2012, 02:40 PM
and if u have kids they may a but something in the back thats loose that u dont know about lol

Prime8
06-28-2012, 05:52 PM
theres not a whole lot on stuff in the back, take a look under to see if something is loose/ or broken, could be ur end links shock bottoming out a loose coil

good luck

I've crawled under there numerous times, both off the ground and on, and shook the LCAs, shocks, springs, track bar, exhaust, rear driveshaft, and trailer hitch. The only thing that nudged was the DS, but I pulled that off and retightened the pinion nut a couple weeks ago.

07rub
06-28-2012, 06:48 PM
the only thing i could see is that ur shocks lost there oil and are bottoming out, i guess the best way to test that idea would just to remove the bottom bolt and feel if the actually do there job lol

Prime8
06-28-2012, 11:32 PM
the only thing i could see is that ur shocks lost there oil and are bottoming out, i guess the best way to test that idea would just to remove the bottom bolt and feel if the actually do there job lol

Wouldn't I notice excessive travel in the rear if that were the case...?

TrailBear
06-29-2012, 12:00 AM
If your shocks are gone the back would have a bit of a bounce to it when going over bumps, you can push up and down on your bumper a few times.

StrizzyChris
06-29-2012, 12:05 AM
This may not be it AT ALL...but have you made sure the nut on the end of your jack stand is tight, keeping it snug in its craddle? :thinking:

Prime8
06-29-2012, 12:58 AM
This may not be it AT ALL...but have you made sure the nut on the end of your jack stand is tight, keeping it snug in its craddle? :thinking:

Easy enough to check, and I actually thought of that last night. The sound seems heavier though. I'll pull it tomorrow and check. It's 102 and humid in Illinois today, so it'll have to wait... Haha. Don't need the stock jack anyways...

piginajeep
06-29-2012, 03:47 AM
Do you have d rings? What control arms are you running ?

Irishcoffee
06-29-2012, 03:52 AM
Rear door noise ?

Prime8
06-29-2012, 04:12 AM
Do you have d rings? What control arms are you running ?

Stock uppers, RK midarm lowers.

Prime8
06-29-2012, 04:14 AM
Rear door noise ?

Tried shaking the tailgate door while closed and open... Nothing. Is there anything internally that would bang around loudly in the tailgate if the third tail light is disconnected....?

Prime8
06-29-2012, 02:48 PM
Now that Eddie is back and posting like crazy, maybe he can weigh in...?

Prime8
06-29-2012, 11:50 PM
Bump for assistance?

TX_JK
06-30-2012, 12:50 AM
Does your JK have the HARDTOP on? I've put my hardtop back on and forgot to re-attach it to the tub which might cause it lift up and make noise when going over bumps?

The other thing you might try is have someone ride in the back and see if they can pin point the sound. Maybe someone riding in the back can either hear the noise or feel it to help locate it.

I'd also crawl under the back of the jeep and put a wrench on everything to just make sure nothings loose. Shock bolts, control arms, trackbar, swaybar, links, bumper bolts, etc...

Do all your exhaust hangers look ok? Plenty of clearance around all your exhaust?

Sharkey
06-30-2012, 01:51 AM
Check to see if the bolts on your swaybar end links are making contact with whatever bumpstop extensions (assuming you are running them) you have on the rear axle perch. I have seen and heard a similar "thunk" on a buddy's Jeep and this is what it turned out to be.

piginajeep
06-30-2012, 04:51 AM
Stock uppers, RK midarm lowers.

Have you check the bushings lately?

Prime8
06-30-2012, 02:31 PM
Have you check the bushings lately?

I have not. But there was some damage to the one rear LCA from improper install, and RK sent me both rear LCAs free! Just haven't installed them yet. The warranty issue isn't something that would cause the clunking, but by swapping out my rear LCAs I'll know if there is a bushing issue.

Prime8
06-30-2012, 02:33 PM
Does your JK have the HARDTOP on? I've put my hardtop back on and forgot to re-attach it to the tub which might cause it lift up and make noise when going over bumps?

The other thing you might try is have someone ride in the back and see if they can pin point the sound. Maybe someone riding in the back can either hear the noise or feel it to help locate it.

I'd also crawl under the back of the jeep and put a wrench on everything to just make sure nothings loose. Shock bolts, control arms, trackbar, swaybar, links, bumper bolts, etc...

Do all your exhaust hangers look ok? Plenty of clearance around all your exhaust?

Trektop nx is currently on. First thought was exhaust, but everything is tight and the clunking is a deep, heavy sound, not so much a rattling noise.

Prime8
06-30-2012, 02:35 PM
Check to see if the bolts on your swaybar end links are making contact with whatever bumpstop extensions (assuming you are running them) you have on the rear axle perch. I have seen and heard a similar "thunk" on a buddy's Jeep and this is what it turned out to be.

I'll check that today when swapping LCAs. LCAs should be swapped one at a time while the vehicle is on the ground, or at least not fully tightened until on the ground, to avoid preloading, right?

Sharkey
06-30-2012, 02:47 PM
I'll check that today when swapping LCAs. LCAs should be swapped one at a time while the vehicle is on the ground, or at least not fully tightened until on the ground, to avoid preloading, right?

You can put them all on, just don't torque to spec until the Jeep is on level ground under full weight. I jump up and down on the bumpers and rock the Jeep side to side first too.

Prime8
06-30-2012, 02:54 PM
You can put them all on, just don't torque to spec until the Jeep is on level ground under full weight. I jump up and down on the bumpers and rock the Jeep side to side first too.

Ok, good to know. Thanks for your help Sharkey.

MTG
06-30-2012, 02:58 PM
Do you have a Tuffy concealed carry drawer? I had a clunk that sounded like it was coming from the rear end but it turned out to be the Tuffy concealed carry drawer. I didn't install the rear screw to the tub and the back end would clunk on bumps. Small piece of wood wedged in there took care of it.

Good luck!

Prime8
06-30-2012, 03:16 PM
Do you have a Tuffy concealed carry drawer? I had a clunk that sounded like it was coming from the rear end but it turned out to be the Tuffy concealed carry drawer. I didn't install the rear screw to the tub and the back end would clunk on bumps. Small piece of wood wedged in there took care of it.

Good luck!

Nope. Carry my guns around attached to my shoulders! Haha. They aren't even registered!

Prime8
06-30-2012, 03:17 PM
You can put them all on, just don't torque to spec until the Jeep is on level ground under full weight. I jump up and down on the bumpers and rock the Jeep side to side first too.

Do you happen to know the torque spec, by chance?

MTG
06-30-2012, 03:48 PM
Do you happen to know the torque spec, by chance?

I believe the control arms are 125 but if you look at project-jk they are all listed.

Prime8
06-30-2012, 06:21 PM
I believe the control arms are 125 but if you look at project-jk they are all listed.

Yeah, I've got that list printed out, out in my garage. Just thought you might know it off the top of your head.

Prime8
06-30-2012, 11:00 PM
SOLUTION!!! I hope...

So as I was crawling around underneath my jeep putting on my new rear LCAs, I was shaking EVERYTHING and looking for any signs of rubbing or banging parts. As a last ditch effort, I started hitting various parts with the side of my fist, to better recreate the impact of bumps on the road... The last thing I was planning to check, the trailer hitch, was a winner! Well, not so much the hitch itself, but the hard plastic bumper cover above it. Seems there is just enough of a gap between the hitch and the plastic cover that it 'clunks' when I hit bumps. It would also explain why the noise would worsen in the afternoons, as the plastic sat in the sun and expanded all day, further reducing the gap so that even smaller bumps would cause the noise. So, I cut out a 2"x2" slice of that 'ergonomic' foam, (the kind of stuff they are putting on floor mats that molds to your feet) and wedged that in the gap while pulling upwards on the bumper cover. Seems to have solved the problem, but I haven't driven it yet.

Thanks to everyone for your suggestions!

Sharkey
06-30-2012, 11:13 PM
Wow...good find! Who would have thunk that could be your clunk in the trunk?

TX_JK
06-30-2012, 11:38 PM
Wow...good find! Who would have thunk that could be your clunk in the trunk?

LOL :rock:

Prime8
06-30-2012, 11:52 PM
Wow...good find! Who would have thunk that could be your clunk in the trunk?

I'm just glad it wasn't voll in my hole... And it surely wasn't a lox in a box.

MTG
07-01-2012, 12:50 AM
I'm just glad it wasn't voll in my hole... And it surely wasn't a lox in a box.

Glad you didn't hesitate, prime eight
To find the clunk in your trunk
Hopefully no more clank in your tank
Or bub in your tub
Here's to next week, being without a squeak!