strange clank noise from back of car.. help please..
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From: Anaheim Hills, CA
strange clank noise from back of car.. help please.. Ok.. this is a pain to diagnose since it only happens when the car is moving.. the sound is like you put marbles or rocks in a can and rolled the can.. it only happens the car is in motion and your going over ANY sort of small bump(s).. Its making me nuts (im starting to wonder if someone put marbles in my tailpipe! <img src="gr_images/icons/wink.gif" border="0">
LS1.com was no help on this (just jokes on muffler bearings <img src="images/icons/rolleyes.gif" border="0"> ) so it up to the tech heads here <img src="gr_stretch.gif" border="0"> TIA
LS1.com was no help on this (just jokes on muffler bearings <img src="images/icons/rolleyes.gif" border="0"> ) so it up to the tech heads here <img src="gr_stretch.gif" border="0"> TIA
Re: strange clank noise from back of car.. help please.. Re-tighten your LCA and panhard bolts. I've had mine off the car 3 times, and I swear, everytime I do, they loosen up right away, and I have to re-tighten them. They make a loud clunk/clank over any and every bump. Enough to drive you crazy. Crank those sumbitches to ~75ft/lbs (dont remember the exact figure, I did 80), and use some loctite on them, WITH the suspension loaded.
Might as well tighten the lower shock bolts while you're there too. If the sound persists, check your rear hatch. I had the rubber bumpers screwed all the way into the hatch, so the hatch could rattle around over certain bumps, and it also flexes the hatch 'lock' mechanism around, creating a loud 'pop' over certain bumps as well.
Finally, check your sway bars. I don't think they'd make the same noise, probably more of a squeek, but it's worth it while you're under there. Add some grease to everything while you're at it as well.
The marbles-in-a-can sound is very common to those with the Torsen diff, and is normal - but I see you have an Auburn. If you STILL have noise after all this, you may want to check to see if the Auburn is still functional (lil burnout to see if you leave 2 marks). If it's working, try adding some GM limited slip additive to the rear, the clutches could be chattering/grinding.
Finally, if you S T I L L have the noise, I'd change the rear end fluid alltogether. It may be low, contaminated, etc.. Be sure to use the additive like I said.
Still there? It's probably something serious, bearings or gears going. Drive it off a cliff. <img src="gr_images/icons/wink.gif" border="0">
Dope, king of the rear-end noises.
Might as well tighten the lower shock bolts while you're there too. If the sound persists, check your rear hatch. I had the rubber bumpers screwed all the way into the hatch, so the hatch could rattle around over certain bumps, and it also flexes the hatch 'lock' mechanism around, creating a loud 'pop' over certain bumps as well.
Finally, check your sway bars. I don't think they'd make the same noise, probably more of a squeek, but it's worth it while you're under there. Add some grease to everything while you're at it as well.
The marbles-in-a-can sound is very common to those with the Torsen diff, and is normal - but I see you have an Auburn. If you STILL have noise after all this, you may want to check to see if the Auburn is still functional (lil burnout to see if you leave 2 marks). If it's working, try adding some GM limited slip additive to the rear, the clutches could be chattering/grinding.
Finally, if you S T I L L have the noise, I'd change the rear end fluid alltogether. It may be low, contaminated, etc.. Be sure to use the additive like I said.
Still there? It's probably something serious, bearings or gears going. Drive it off a cliff. <img src="gr_images/icons/wink.gif" border="0">
Dope, king of the rear-end noises.
