Rear axle nuts
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Here you go, from our archives:
Subject: Tapping or Scraping Noise From Rear Wheel Area (Replace Wheel Drive Shaft Nut) #07-04-95-001 - (09/26/2007)
Models: 2005-2008 Cadillac XLR
2005-2008 Chevrolet Corvette
Condition
Some customers may comment on a tapping or a scraping noise coming from the rear wheel area.
Cause
This condition may be due to the torque on the wheel drive shaft nut relaxing over time.
Correction
Replace the left and the right wheel drive shaft nut following the procedure below.
Remove the center cap from the rim.
Remove and discard the wheel drive shaft nut.
Apply LOCTITE™ 272, or equivalent, to the threads of the axle shaft.
Install the nut and tighten to the new specification.
Tighten
Tighten the nut to 215 N·m (160 lb ft).
Install the center cap to the rim.
Important: The vehicle should not be driven for 24 hours following the repair in order to allow the thread lock to cure.
Part Number
Description
Qty
10257766
Nut
2 (one per side)
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
F9712*
Wheel Drive Shaft Nut - Replace
0.3 hr
*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
Subject: Tapping or Scraping Noise From Rear Wheel Area (Replace Wheel Drive Shaft Nut) #07-04-95-001 - (09/26/2007)
Models: 2005-2008 Cadillac XLR
2005-2008 Chevrolet Corvette
Condition
Some customers may comment on a tapping or a scraping noise coming from the rear wheel area.
Cause
This condition may be due to the torque on the wheel drive shaft nut relaxing over time.
Correction
Replace the left and the right wheel drive shaft nut following the procedure below.
Remove the center cap from the rim.
Remove and discard the wheel drive shaft nut.
Apply LOCTITE™ 272, or equivalent, to the threads of the axle shaft.
Install the nut and tighten to the new specification.
Tighten
Tighten the nut to 215 N·m (160 lb ft).
Install the center cap to the rim.
Important: The vehicle should not be driven for 24 hours following the repair in order to allow the thread lock to cure.
Part Number
Description
Qty
10257766
Nut
2 (one per side)
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
F9712*
Wheel Drive Shaft Nut - Replace
0.3 hr
*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
33mm fit my axle nut perfectly, but it may depend on the tolerances of the brand socket you find.
Basically, 1 5/16" is the equivalent to 33mm.
33mm/25.4 mm per inch = 1.299 inches.
5/16 = .3125 inches, a difference of a little over 1/100th of an inch. (.0135)
I also read in some post where the C5 axles were stronger than the ones used for the C6, and some people are going back with the C5 axles.
Basically, 1 5/16" is the equivalent to 33mm.
33mm/25.4 mm per inch = 1.299 inches.
5/16 = .3125 inches, a difference of a little over 1/100th of an inch. (.0135)
I also read in some post where the C5 axles were stronger than the ones used for the C6, and some people are going back with the C5 axles.
Last edited by TEXHAWK0; Oct 18, 2008 at 01:14 PM.
Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
I picked up a 33mm deep socket from Pep Boys which fits the rear axle nuts of my 06 Vert perfectly. However, after reading all the pro's and con's of continuing to torque the rear axle nuts to 118 lbs, I am going to relax my concern with this issue.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Melting Slicks
Joined: Sep 2005
Posts: 2,670
Likes: 134
From: merritt island fl
C1 of Year Finalist (stock) 2019
2016 C1 of the Year Finalist
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I'm confused.
Is the issue with the stronger C-5 AXLES the axle shaft itself? The nut issue is on the C-V joint stub shaft- not the axle itself. I know the terminology is confusing but I think we have two separate, but possibly related issues.
On the nuts loosening:
I can't believe tightening the nuts to 180 ft-lbs comes anywhere close to causing the stub shaft to stretch. However, a really big torque motor, coupled with sticky tires that really hook up, COULD "twist" the C-V stub shaft enough to cause stretch. I haven't run the numbers to see if it is reasonable, however.
Is the issue with the stronger C-5 AXLES the axle shaft itself? The nut issue is on the C-V joint stub shaft- not the axle itself. I know the terminology is confusing but I think we have two separate, but possibly related issues.
On the nuts loosening:
I can't believe tightening the nuts to 180 ft-lbs comes anywhere close to causing the stub shaft to stretch. However, a really big torque motor, coupled with sticky tires that really hook up, COULD "twist" the C-V stub shaft enough to cause stretch. I haven't run the numbers to see if it is reasonable, however.
Le Mans Master
Joined: Feb 2006
Posts: 5,762
Likes: 4
From: Chandler Arizona
On the nuts loosening:
I can't believe tightening the nuts to 180 ft-lbs comes anywhere close to causing the stub shaft to stretch. However, a really big torque motor, coupled with sticky tires that really hook up, COULD "twist" the C-V stub shaft enough to cause stretch. I haven't run the numbers to see if it is reasonable, however.
I can't believe tightening the nuts to 180 ft-lbs comes anywhere close to causing the stub shaft to stretch. However, a really big torque motor, coupled with sticky tires that really hook up, COULD "twist" the C-V stub shaft enough to cause stretch. I haven't run the numbers to see if it is reasonable, however.
I have run the numbers. A good rule of thumb for lubricated threads is: Torque = .2 x Force x diameter which can also be rearranged to be Force = Torque / (.2 x diameter). I think the thread is slightly above 1", but let's use 1" for worst case: F = 180 (12) / .2 = 10,800 pounds force. (the 12 is there to convert inches to feet).The area of a 1" shaft is .785 in2. So the stress just due to torqueing the nut is 10,800/.785 = 13,758 psi. That is NOTHING for a good hard steel. A typical stub material should be good for at least 80,000 psi.
Melting Slicks
Joined: Sep 2005
Posts: 2,670
Likes: 134
From: merritt island fl
C1 of Year Finalist (stock) 2019
2016 C1 of the Year Finalist
2015 C2 of the Year Finalist
I have run the numbers. A good rule of thumb for lubricated threads is: Torque = .2 x Force x diameter which can also be rearranged to be Force = Torque / (.2 x diameter). I think the thread is slightly above 1", but let's use 1" for worst case: F = 180 (12) / .2 = 10,800 pounds force. (the 12 is there to convert inches to feet).The area of a 1" shaft is .785 in2. So the stress just due to torqueing the nut is 10,800/.785 = 13,758 psi. That is NOTHING for a good hard steel. A typical stub material should be good for at least 80,000 psi.
I think there are 2 related but different issues here:
1. Some cars came from the factory with "loose" nuts.
2. Some cars are "stretching" the C-V sharts, with resultant nut loosening, due to high torque applications at the C-V shafts from big motor/ hard driving applications.
It looks to me like the C-V joints are at the limit of their strength.
I wonder if the ZR-1 C-V joints are the same. If so, I'd expect to see troble there.
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Instructor
Joined: Aug 2008
Posts: 103
Likes: 0
From: Cumming GA
Good post, I was having a popping noise in the back and brought it to the dealership today. I was told there are revised bolts/use of locktite on the axle bolts. I am bringing my car back in Thursday to have this done because the car has to sit overnight. I hope this resolves the issue. I think they tightened the bolts today in the mean time because the noise is 80% gone. They are not charging me money which is always good.
Drifting
Joined: Aug 2005
Posts: 1,645
Likes: 90
From: Sparks NV
Was having the clicking on my 05 Z51 mn6 with 36k mi. Driver side was loose. Pulled the nuts, sprayed Royal Purple Maxfilm penetrating lube where the axel shaft and hub meet, applied blue Locitite and retorqued to 120 ftlbs. Let stand 24hrs. 1000 miles later still no noises. Quite as new.
Anxious to see how long this will last but seems to work. Now if I could stop the exhaust rattle.
H
Anxious to see how long this will last but seems to work. Now if I could stop the exhaust rattle.
H
Racer
Joined: Apr 2012
Posts: 314
Likes: 4
From: Ontario
Torque Spec
We have a 14K mile 2005 base Corvette. I see specs. of 116, 151 and 160 ft/lb torque. Someone must know which is correct. I can see me springing the couple of hundred dollars for the service manual. I've always been a do it yourselfer with the old Chevelles. With the Corvette, I might have to stretch the old brain cells but the challenge is needed to keep the mind working.
Thanks
Thanks
Racer
Joined: Apr 2006
Posts: 486
Likes: 2
From: The Villages FL
Keith, Please read my old post on this subject. Post #219. My car now has 38k miles on it with no problems at all. The nut is actually and assembly aid to installing the half shaft into the wheel bearing assembly. To properly seat the shaft into the bearing 118 lb-ft torque is all that is required. Why GM specified a higher torque on this nut via a TSB is beyond me. Do not fall into the trap of using higher torques or repeated retorquing of this nut. Follow my post and then fugetaboutit. Enjoy your car. Bill S.
Racer
Joined: Apr 2012
Posts: 314
Likes: 4
From: Ontario
Nut Torque
Thanks Bill. I was just talking to my GM parts guy and I think I will buy the service manual for my car. It's somewhere around $200 but will be worth it. Back in '69, when I bought the Chevelle, I think I paid GM $3 for the big manual. It's pretty well dog eared now and it paid for itself many times over. Everyone should own one if they are thinking of doing anything on their cars. I have a lot to learn about the C6.
