The Old Mysterious "Clunk" when moving

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deckroid
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The Old Mysterious "Clunk" when moving

Postby deckroid » Sun Jan 28, 2018 1:30 pm

Hey all,

My 84 Grand Wagoneer, which I love but keeps me guessing on the next trouble spot, has developed a new thing. When I am stopping or starting, not in reverse, only forward, I am getting a "Clunk" that feels towards the rear. I could be wrong.

I just, like 2 weeks ago, replaced my RMS, oil pan gasket and tranny gasket. It's a stock auto, stock motor, lifted but not crazy like 6+"... I have gotten under and looked at the U-Bolts, tried to shake the drive line, but there was no play. Granted, I had it in Park, so maybe I need to have it in Neutral? My biggest fear is either I screwed up the transmission when changing the filter and gasket or, and this keeps me up at night, the rear axle. U-Joints, even at my place without a press, aren't horrible to change. Once you know the 13mm socket trick.

I looked though older posts and most of what I have learned is U-Bolt or Tranny Mount to the motor. And, yeah, I did play with that a bit when I redid the RMS, but I am not leaking ATF.

Any help, direction, suggestions and scoffing would be greatly appreciated.
George

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Gumby
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Re: The Old Mysterious "Clunk" when moving

Postby Gumby » Sun Jan 28, 2018 9:23 pm

I had the same clunk... Well still do just not as bad. I got into the rear drums and it went silent for a long time, also check that rear drive shaft u joints.
1984 GW 360/727/208.... 4"/ 31"
2004 CRD QC SRW 3500 4X4 (DD)
1983 "project Dubya" (long term)

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Tatsadasayago
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Re: The Old Mysterious "Clunk" when moving

Postby Tatsadasayago » Mon Jan 29, 2018 1:39 am

There are so many parts that can cause this clunk George. Since yours is an 84, I would first look at the passenger side wheel bearing as the source. After that, I'd look at the rear axle carrier bearings and spider gears. Next would be rear axle pinion bearings and driveshaft. Failing that, I'd look at the trans/transfer case and engine mounts. Lastly, I would look at the transfer case chain as it will cause a clunk under power if it's stretched. It could be you are hearing the chain jumping on the drive sprocket.
1977 Cherokee Chief - The Blair Jeep Project III
A collection of parts flying in close formation

candymancan
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Re: The Old Mysterious "Clunk" when moving

Postby candymancan » Mon Jan 29, 2018 4:51 am

My 249 transfercase chain is stretched i suspect and it causes a loud clunk or slam when in gear or reverse if i dont hold the brake and let it pick up slack first.

Check u joints thats easy..

Screwing up a transmission by changing fluid is a myth... Ive flushed all 3 Jeeps within the last year with 14-15 quarts of dexron 3 for the waggy and atf4 for the ZJs. probly more like 25 quarts in the wagoneer because of how bad the shift shaft seal was leaking for a year i had to refill with a quart every week or 2 before i fixed it lol

just pull the cooler outlet line.. pop it through gears while a buddy watchs the milk jug fill and have him yell to turn the engine off when its near full.

1 gallon is 4 quarts. then refill with 4 and repeat until yoy do 12-16 quarts depending in what tranny you got. of course change the filter first. The 42re in the 4.0 is pushing 260k original miles soon.. Its only now starting to act up and i suspect it might just be a solenoid. The 46re in my 5.9zj is at 191k.. and my wagoneer is at 126k now.

Anyway i suspect tge clunk is probly something in your differential or transfercase chain slack
2013 SS camaro, cammed, and modded too much to say 500 RWHP/650 crank 30k
1998 Jeep Grand Cherokee 5.9L Limited 191k
1998 Jeep Grand Cherokee 4.0 I6 laredo 256k
1990 Jeep Grand Wagoneer 126k

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Stuka
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Re: The Old Mysterious "Clunk" when moving

Postby Stuka » Mon Jan 29, 2018 8:27 am

Here is what I would do first, and please be careful with this. Put your parking brake on, block the tires, and have somebody else shift it into drive. While they do this first look under the hood, see how much the engine moves. Then you can look underneath (from the SIDE, don't go underneath) while they do the same thing. You should be able to localize the sound.

Just be careful :)
1981 J10 AMC 258 with HEI and Weber 32/36 DGEV Carb, T176, NP208, D44/M23 with 4.56 gears and Detroit Locker, 6" lift, 33x12.50 Cooper STT's, BJ's Offroad Rear Dozer Bumper.
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az chip
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Re: The Old Mysterious "Clunk" when moving

Postby az chip » Mon Jan 29, 2018 8:58 am

I had clunking once when starting or stopping. My lug nuts were loose.
'81 Cherokee Chief 81 WT Chief/MSD 6/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/ H4 Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

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fulsizjeep
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Re: The Old Mysterious "Clunk" when moving

Postby fulsizjeep » Mon Jan 29, 2018 11:58 am

Loose nuts are dangerous. :fsj:
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88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s, a few Evil Twin mods, http://eviltwinfab.com and a few TT's Fabworks mods, http://www.ttsfabworks.com
76 401 Wag, 77 401 Wag, 77 401 J20

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deckroid
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Re: The Old Mysterious "Clunk" when moving

Postby deckroid » Mon Jan 29, 2018 7:20 pm

... but I just can't commit to tighty whiteys anymore. When I was 11, sure, but now? It's not the 70s anymore.

Tomorrow I plan on jacking the jeep up and seeing what happens when I put it in gear. I am hoping there is just excess mud or something in the rear drum breaks. I have a buddy coming over to help out so I don't kill myself doing something fool hardy.

letank
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Re: The Old Mysterious "Clunk" when moving

Postby letank » Tue Jan 30, 2018 12:05 pm

Stuka wrote:Here is what I would do first, and please be careful with this. Put your parking brake on, block the tires, and have somebody else shift it into drive. While they do this first look under the hood, see how much the engine moves. Then you can look underneath (from the SIDE, don't go underneath) while they do the same thing. You should be able to localize the sound.

Just be careful :)


Utility poles "the fat wooden ones" are perfect for that test, place the bumper against the pole... and proceed as described above
Michel
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az chip
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Re: The Old Mysterious "Clunk" when moving

Postby az chip » Tue Jan 30, 2018 2:29 pm

fulsizjeep wrote:Loose nuts are dangerous. :fsj:


There is no law against them. :shock:
'81 Cherokee Chief 81 WT Chief/MSD 6/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/ H4 Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

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fulsizjeep
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Re: The Old Mysterious "Clunk" when moving

Postby fulsizjeep » Wed Jan 31, 2018 6:32 am

That's amazing for Arizona! Arrive on vacation, depart on probation. ;)
Sent from my IBM 5150 using TN5250 emulation.

Flint Boardman ~ http://jubileejeeps.org
Embracing the Borg Warner QuadraTrac since 1980 http://jubileejeeps.org/quadratrac
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s, a few Evil Twin mods, http://eviltwinfab.com and a few TT's Fabworks mods, http://www.ttsfabworks.com
76 401 Wag, 77 401 Wag, 77 401 J20

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deckroid
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Re: The Old Mysterious "Clunk" when moving

Postby deckroid » Fri Feb 02, 2018 3:54 pm

Ok, jacked it up 3 times, put into gear, and nothing. No sound. Let her back down, drove a bit and the clunk came back but only after being driven for more than 20 mins.

This has now moved from Annoying to Aggravating. Checked lug nuts. They were tight. (Insert tight nut joke here). The U Bolts look good, no real jerky movements... I am thinking of installing a GoPro underneath to try and catch anything.

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az chip
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Re: The Old Mysterious "Clunk" when moving

Postby az chip » Sun Feb 04, 2018 12:57 am

Dang it.
'81 Cherokee Chief 81 WT Chief/MSD 6/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/ H4 Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

FSJ Guy
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Re: The Old Mysterious "Clunk" when moving

Postby FSJ Guy » Wed Feb 07, 2018 10:22 am

X2 on either motor mounts or transmission mount. Lift the transmission or engine with a floor jack (use a board to distribute the load) slightly and see if they mounts move. Replace them with poly mounts if they're bad and you'll never replace motor mounts ever again.
:- )
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Jeepless, but I still have a lots of old parts in my garage!

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deckroid
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Re: The Old Mysterious "Clunk" when moving

Postby deckroid » Thu Feb 08, 2018 7:33 am

Found it! The linkage itself was fine, but the movement was stunted on the part that the linkage attaches to on the tranny itself. It wasn't allowing for full movement and was bypassing 2nd gear. I must have "broken" it when I was swearing and beating on stuff under there while installing my RMS. It's all kind of a red haze now, but I think I do recall throwing wrenches around and swearing like drunk sailors who just got a 4 day pass in Bangkok revoked.

Thanks everyone!

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Re: The Old Mysterious "Clunk" when moving

Postby FSJ Guy » Fri Feb 09, 2018 3:23 pm

That's got to be one of the more colorfully descriptive resolutions posted here in a long time!! LOL!!
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Jeepless, but I still have a lots of old parts in my garage!

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Re: The Old Mysterious "Clunk" when moving

Postby Cheapthrills » Sun Feb 25, 2018 11:12 am

fulsizjeep wrote:That's amazing for Arizona! Arrive on vacation, depart on probation. ;)
I thought that was just Clark county Nevada

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