Rear Knock

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Cheever3
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Rear Knock

Unread post by Cheever3 »

So I've talked to some of you about the knock coming from the rear driver of my JK. I removed the shock from that side and the noise has stopped. I've taken a look at the bushings but they look fine. Ive also taken a look at the mounts and besides some rust, they look fine too.

Is it just time to replace the shocks?

Thanks

Bill
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RalphTomaccio
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Re: Rear Knock

Unread post by RalphTomaccio »

They stopped selling shocks for your Jeep. You have to buy a new one! Time to go shopping. :-o
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Frank
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Re: Rear Knock

Unread post by Frank »

If you collapse and open the shock in your hands does it make noise. Not how far you move it , how quick . If the noise stopped , it has to be the shock and or the mounts. You could put the bolts into the bushings and if there is any play that would be the noise. A shock usually is dead by 50k on the street but we do a little more to them than that. How old are they in miles ? Stock shocks arent that good once we lift and put big tires. FjR68
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MDSRACING398
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Re: Rear Knock

Unread post by MDSRACING398 »

If one of the bolts was a little loose the bolt will make a KNOCK also. Glad you atleast kind of figured it out.
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Cheever3
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Re: Rear Knock

Unread post by Cheever3 »

Frank wrote:If you collapse and open the shock in your hands does it make noise. Not how far you move it , how quick . If the noise stopped , it has to be the shock and or the mounts. You could put the bolts into the bushings and if there is any play that would be the noise. A shock usually is dead by 50k on the street but we do a little more to them than that. How old are they in miles ? Stock shocks arent that good once we lift and put big tires. FjR68
They have 40k plus on them. There is still a lot of resistance on she shock when I try to collapse it...no noise. I'll have to check the bolts in the bushings.

Thanks for the help.

Bill
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Frank
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Re: Rear Knock

Unread post by Frank »

Cheever3 This being the members section , you will only get responses from a member. If you had put this question in the Tech section , its open to the public and many more people that have your type of Jeep could respond to it . FYI FjR68
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RalphTomaccio
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Re: Rear Knock

Unread post by RalphTomaccio »

Frank wrote:Cheever3 This being the members section , you will only get responses from a member. If you had put this question in the Tech section , its open to the public and many more people that have your type of Jeep could respond to it . FYI FjR68
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MDSRACING398
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Re: Rear Knock

Unread post by MDSRACING398 »

Just looked under a Jk to see what looks like.

ld bet it's the top bar pin on shock or loose bolt bolting pin in. They make bar pin eliminators to fix the problem.
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Cheever3
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Re: Rear Knock

Unread post by Cheever3 »

So I took the shock off and took a look at the lower bushing and there was the issue. The metal sleeve that runs through the rubber bushing is not threaded, but the factory bolt was threaded from top to bottom. Over time the threading that runs through the bushing was completely worm away giving the bolt just enough wiggle room inside the bushing to move around. I went to the hardware store and bought new bolts for the lower mounting points. The bolts are Grade 10.9 M12x1.5x70. I wasn't able to find a flange head bolt...the ones I picked up have a body that runs all the way through the bushing. Hopefully that will eliminate the wear issue that happened with the factory bolts.

The noise has stopped since this fix. Would it be necessary to find a flange head bolt? They are inexpensive, I'm not sure what the difference would be in this case?
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Re: Rear Knock

Unread post by Kurt »

Just put a GR8 flat washer under the head of the new bolt.
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Cheever3
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Re: Rear Knock

Unread post by Cheever3 »

Sounds good. Thanks
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pirahnah3
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Re: Rear Knock

Unread post by pirahnah3 »

Awesome, glad you found the solution and it was an easy one. As Ken stated a simple washer will do the job with no problem.
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RalphTomaccio
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Re: Rear Knock

Unread post by RalphTomaccio »

Hey, Bill, good going on your persistence in trying to locate your noise source. Glad you found it! Was the bushing worn as well or just the bolt threads?
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Frank
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Re: Rear Knock

Unread post by Frank »

No Charge Dude ! Yer welcome :) FjR68
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Cheever3
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Re: Rear Knock

Unread post by Cheever3 »

Its like being able to reach an itch that I couldn't scratch. Thanks everyone for your help.

Ralph- The bushings were fine. A little bit of wear on the metal sleeve from the old bolt but thats about it.
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