"Lag" in drivetrain?

Devallee

Devallee

New member
I'm getting an odd clanking sound in the rear sort of like metal hitting metal, like when two moving pieces are screwed together but the screw is loose? (Sorry for the terrible description) I hear it whenever I go over any type of bump or little potholes in the street it's incredibly annoying. But I've also noticed that when I tap on the gas I can hear the sound as well. It's like I tap the gas pedal and the driveshaft is trying to catch up and it makes that clanking sound thats why I think I've narrowed it down to the driveshaft. I've tried making sure everything is tight but I can't figure it out and most shops want at around $100 just to take a look. Anybody had this issue before or understand my horrible explanation and could maybe help out? I'd appreciate it it's driving me nuts. Maybe I can try to get a video tomorrow of the sound and post it up if that will help explain :idontknow:
 
I would torques check all componets to include shocks and if you have them spring retainers. Sounds like you might have something loose. If memory serves me correct Eddie broke a rear trackbar axle mount on the JKX in Colorado. He had an annoying squeak and when it broke the squeak went away. I think it was video three.

Interested in finding out what the solution is.

R/
Will
 
Devallee said:
I'm getting an odd clanking sound in the rear sort of like metal hitting metal, like when two moving pieces are screwed together but the screw is loose? (Sorry for the terrible description) I hear it whenever I go over any type of bump or little potholes in the street it's incredibly annoying. But I've also noticed that when I tap on the gas I can hear the sound as well. It's like I tap the gas pedal and the driveshaft is trying to catch up and it makes that clanking sound thats why I think I've narrowed it down to the driveshaft. I've tried making sure everything is tight but I can't figure it out and most shops want at around $100 just to take a look. Anybody had this issue before or understand my horrible explanation and could maybe help out? I'd appreciate it it's driving me nuts. Maybe I can try to get a video tomorrow of the sound and post it up if that will help explain :idontknow:
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Sounds like you either have a loose suspension component bolt or blown bushing somewhere or a mount starting to tear. This is something you would hear even when you accelerate as your suspension will shift with the changing load. I would check your rear upper control arms and mounts as well as the track bar.
 
I had a similar issue at least in terms of clanking sound and catch up feeling in my TJ. Turned out to be a U joint and centering ball in my rear driveshaft. The u joint seemed fine but when I took it out the needle bearings were fried and the joint itself ground down. I have a double cardan joint I'm not sure if the JKs have them.

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wayoflife said:
Sounds like you either have a loose suspension component bolt or blown bushing somewhere or a mount starting to tear. This is something you would hear even when you accelerate as your suspension will shift with the changing load. I would check your rear upper control arms and mounts as well as the track bar.
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I thought I mentioned it but looking at my post I obviously didnt but...the sound stops whenever I have my foot on the brake. If I'm driving on a bumpy road or over a speed bump while on the brakes there's no sound. I thought it was my brakes but they seem fine. And that lag feeling when I accelerate brought me away from the brakes so I don't know what else I can check :thinking: but I will check bushings I didn't check those originally thank you
 
RuffneckTwoZero said:
I had a similar issue at least in terms of clanking sound and catch up feeling in my TJ. Turned out to be a U joint and centering ball in my rear driveshaft. The u joint seemed fine but when I took it out the needle bearings were fried and the joint itself ground down. I have a double cardan joint I'm not sure if the JKs have them.

<img src="http://wayalife.com/attachment.php?attachmentid=41054"/>
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I have the stock driveshaft which is not a double cardin but thank you for the input
 
wayoflife said:
Sounds like you either have a loose suspension component bolt or blown bushing somewhere or a mount starting to tear. This is something you would hear even when you accelerate as your suspension will shift with the changing load. I would check your rear upper control arms and mounts as well as the track bar.
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It was the rear upper control arm axle mounted bolt. Thanks for the help! I have to say that I've never worked on these type of eccentric bolts (that's what my neighbor told me they were) with these off centered washers welded to the bolt/nut and they're a pain in the ass. Is there a specific way I should be going about tightening them? I got it tight enough to where its not clanking around but I'm not sure if I did it correctly or just tightened it enough to stop the noise for now. I tightened the bolt side until the washer hit that little nub (don't know the mechanical name) then held it in place while I tightened the nut down. Is that correct? Or is there a different or more correct way to ensure it stays tight?
 
Devallee said:
It was the rear upper control arm axle mounted bolt. Thanks for the help! I have to say that I've never worked on these type of eccentric bolts (that's what my neighbor told me they were) with these off centered washers welded to the bolt/nut and they're a pain in the ass. Is there a specific way I should be going about tightening them? I got it tight enough to where its not clanking around but I'm not sure if I did it correctly or just tightened it enough to stop the noise for now. I tightened the bolt side until the washer hit that little nub (don't know the mechanical name) then held it in place while I tightened the nut down. Is that correct? Or is there a different or more correct way to ensure it stays tight?
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that's correct, just make sure to tighten it to the proper torque - 125 Ft lbs
 
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