Clunk in rear when making slow turns like pulling out
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Joined: Apr 2014
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From: Washington Township Michigan
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Possible differential clutch plates, may be time for a rear axle fluid change...…………
Another possibility is loose axle shaft retaining nuts...………. a lot of information about them here in older topics.
Another possibility is loose axle shaft retaining nuts...………. a lot of information about them here in older topics.
Retired & lovin' it!
Joined: Mar 2005
Posts: 4,475
Likes: 549
From: Jackson NJ
Two most common causes of that noise are loose axle nuts, or loss of friction in the posi diff fluid. Either is an easy DIY fix.
You can check the axle nuts with a 33mm socket & torque wrench....factory spec. is 140 lbs. If you find them loose, they should be replaced. GM p/n 10257766...just a couple of bucks each. You don't have to pull the wheels....just remove the center wheel cap to access the nuts. I used Loctite Red; torque to 140 lbs & allow to cure overnight.
If the nuts are tight, then next most common fix is to replace the diff fluid. Correct fluid is Dexron LS Gear oil, GM p/n 88862624. This fluid has the correct friction modifier & no additive is required. When draining the old fluid, always loosen the fill plug first.....you don't want to drain the diff & then find you can't remove the fill plug. Once filled to the proper level, find a nearby parking lot & do 8-10 slow figure 8's.....purpose is to drive the new fluid into the diff clutch plates.
One or the other of these fixes should eliminate the noise.
You can check the axle nuts with a 33mm socket & torque wrench....factory spec. is 140 lbs. If you find them loose, they should be replaced. GM p/n 10257766...just a couple of bucks each. You don't have to pull the wheels....just remove the center wheel cap to access the nuts. I used Loctite Red; torque to 140 lbs & allow to cure overnight.
If the nuts are tight, then next most common fix is to replace the diff fluid. Correct fluid is Dexron LS Gear oil, GM p/n 88862624. This fluid has the correct friction modifier & no additive is required. When draining the old fluid, always loosen the fill plug first.....you don't want to drain the diff & then find you can't remove the fill plug. Once filled to the proper level, find a nearby parking lot & do 8-10 slow figure 8's.....purpose is to drive the new fluid into the diff clutch plates.
One or the other of these fixes should eliminate the noise.
