Clunking from rear when turning
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Joined: Nov 2007
Posts: 65
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From: Baton Rouge LA
Clunking from rear when turning
I have a 2008 Z51 with 7500 miles. It has never been raced or really driven hard. I am now getting a clunking noise coming from the rear when I turn, either direction. I hear/notice it at low speeds. Anyone know what is causing this and if it will be covered under warranty?
Burning Brakes
Joined: Nov 2008
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From: Long Island NY
Race Director
Joined: Mar 2005
Posts: 10,399
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From: Austin Texas
Call your Dealer service dept and complain of the noise. Ask for Warranty service (the fluid change to the new differential fluid). There was a Tech bulletin about it . With luck they'll do it under Warranty, no luck and you'll have to pay for it.
Worked on my '08 in 2010.
Worked on my '08 in 2010.
Race Director
Joined: Mar 2010
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08Z51,
Getting your rear differential fluid changed may resolve the issue. However, this is something that may not fall under your warranty coverage as it's technically a maintenance service. I would recommend contacting your dealership and trying to work with them to resolve the issue. I'd be more than happy to contact them for you.
Chevrolet Customer Service,
Justin
Getting your rear differential fluid changed may resolve the issue. However, this is something that may not fall under your warranty coverage as it's technically a maintenance service. I would recommend contacting your dealership and trying to work with them to resolve the issue. I'd be more than happy to contact them for you.
Chevrolet Customer Service,
Justin
Melting Slicks
Joined: Jul 2010
Posts: 2,999
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From: Surprise, Az
I believe there was a TSB on this with regards to changing the differential fluid. The new fluid had friction modifiers with it, replacing the fluid in my '08 Z51 cured the problem, what I heard was a clunking from the rear end, in the morning when first starting out (cold differential), apparently the clutches in the rear end have a tendency to stick together when cold so that first drive in the AM would break them loose as I turned out of the driveway (I back my cars in). When the dealer replaced the gear oil, they drove in tight circles to fully lubricate the differential (figure 8's a couple of times). Numerous posts regarding this if you want to do the procedure yourself.
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Joined: Jul 2005
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From: Fresno California
I had this issue a few years ago.. Swap out the fluid in the differential. I tried royal purple.. and that solved it for a month.. Then swapped it with Amsoil severe gear, and a tube of the sliplock additive.. been smooth and no clunking/differential noise for over 2 years now..
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From: King George VA
I had this issue a few years ago.. Swap out the fluid in the differential. I tried royal purple.. and that solved it for a month.. Then swapped it with Amsoil severe gear, and a tube of the sliplock additive.. been smooth and no clunking/differential noise for over 2 years now..
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
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Burning Brakes
Joined: Apr 2008
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From: CARSON HILLS ca
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
Melting Slicks
Joined: Dec 2006
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Having the same issue with my brand new '12 GS MZ6 with only 10 miles on the clock, so it's got to be normal. Or at least not a problem 
. Thought I clipped something when turning full lock to clear the trailer's ramp. Drove it the mile home and haven't touched it due to lack of documents. Just got the MSO today, so will get the plates tomorrow. I plan to make a few figure 8s; that's supposed to make things better. If not, then I'd change the fluid. You'd think GM would be putting the good stuff by now 
.
I plan to use Royal Purple. But what's the viscosity? 75/90 or 75/140? Put RP MaxGear 75/140 on my M3 and it fixed the moaning. I also put RP Synchromax in the tranny and made a big difference. Do our trannies use Synchromax too? And how many quarts in the tranny? My GTO took 4.6, but it was the T56. Our TR-6060 should be the same or pretty close. Thanks gang.
. Thought I clipped something when turning full lock to clear the trailer's ramp. Drove it the mile home and haven't touched it due to lack of documents. Just got the MSO today, so will get the plates tomorrow. I plan to make a few figure 8s; that's supposed to make things better. If not, then I'd change the fluid. You'd think GM would be putting the good stuff by now .I plan to use Royal Purple. But what's the viscosity? 75/90 or 75/140? Put RP MaxGear 75/140 on my M3 and it fixed the moaning. I also put RP Synchromax in the tranny and made a big difference. Do our trannies use Synchromax too? And how many quarts in the tranny? My GTO took 4.6, but it was the T56. Our TR-6060 should be the same or pretty close. Thanks gang.
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Joined: Mar 2005
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From: Austin Texas
Having the same issue with my brand new '12 GS MZ6 with only 10 miles on the clock, so it's got to be normal. Or at least not a problem . Thought I clipped something when turning full lock to clear the trailer's ramp. Drove it the mile home and haven't touched it due to lack of documents. Just got the MSO today, so will get the plates tomorrow. I plan to make a few figure 8s; that's supposed to make things better. If not, then I'd change the fluid. You'd think GM would be putting the good stuff by now .
I plan to use Royal Purple. But what's the viscosity? 75/90 or 75/140? Put RP MaxGear 75/140 on my M3 and it fixed the moaning. I also put RP Synchromax in the tranny and made a big difference. Do our trannies use Synchromax too? And how many quarts in the tranny? My GTO took 4.6, but it was the T56. Our TR-6060 should be the same or pretty close. Thanks gang.
. Thought I clipped something when turning full lock to clear the trailer's ramp. Drove it the mile home and haven't touched it due to lack of documents. Just got the MSO today, so will get the plates tomorrow. I plan to make a few figure 8s; that's supposed to make things better. If not, then I'd change the fluid. You'd think GM would be putting the good stuff by now .I plan to use Royal Purple. But what's the viscosity? 75/90 or 75/140? Put RP MaxGear 75/140 on my M3 and it fixed the moaning. I also put RP Synchromax in the tranny and made a big difference. Do our trannies use Synchromax too? And how many quarts in the tranny? My GTO took 4.6, but it was the T56. Our TR-6060 should be the same or pretty close. Thanks gang.
Most likely the front tires scrubbing at full lock slow speed turns. There is no solution other than don't do full lock turns, it's a function of the design of the steering geometry and wide tires. It's present in all C6's.