Awesome explanation!! Thanks!

 

Checked my axle nuts with a 1 5/16" socket which worked fine, both were about 30 degrees loose @ 3600 miles. Going to get a second pair of nuts and try the double nut idea. Seems like if the nuts came off, hopefully the center cap would capture them and you could hear them rolling around at a slow speed!!!!

 

Worked GREAT! Thanks.

 

Just checked my axle nuts tonight... it's been about 2k miles since I last checked them.

Last time I checked them was the first time I ever checked them, the driver's side was nice and tight (at least 118 ft/lbs) but the passenger side was at 50 ft/lbs... so I tighened it to about 118 ft/lbs.

Now, just 2k miles later, no drag racing, no burn-outs, no abuse, the driver's side axle nut is still tight (as it always was), but the passenger side nut loosened up again. ??? It wasn't bad, may have been at about 80 ft/lbs... took a little movement to get it back to 118 ft/lbs.

I figured that after the intial tightening of the passenger side bolt, it would stay tight, especially the way I drive. I do often go deep into the throttle and run the twisties pretty hard, but I never "launch" hard from a stop or do anything to "abuse" the drivetrain / axles. In other words, I use the power but I am generally gentle on the drivetrain.

What I should have done originally was paint a line on the axle shaft and nuts, this way I would be able to tell if the nuts had moved at all. My original theory (could be wrong) was that the nuts are not backing off, but play is forming due to wear and movement of the parts causing the effective torque on the nuts to become reduced... thus loctiting the nuts, double-nutting etc would not help. I should go down now and paint a line on my passenger side nut / axle shaft. But I'm feeling kinda lazy right now... has anyone tried this? Any evidence of nuts actually backing off?

I think I will stick to my method of just checking the nut torque at roughly every oil change... this way I know the torque is correct regardless of what might be "loosening" up.

 

 

DO NOT DO THIS

This is the exact pitfall I warned people about last time I saw this issue in a thread. My experiement was predicated by the fact that I snapped two axles on the passenger side. Both of them snapped at the point where the axle goes through the hub. The first nut actually came off and I didnt know it. The axle cant fall off the car. With the suspension disassembled, its still hard to get it out. I then did what this guy did and tightened it.....but not knowing I was TQing a strethced spindle. Overtightening the axle nuts pulls along the axle stretching it. After the second and knowing I was reading the TQ wrench properly, I installed the 3rd axle and this time I marked the axle nut and the axle with a marker indicating where the two are in relation to each other. When I went to check the nuts only 200 miles later I noticed first that it was at only 80ft pounds but the marks didnt move. Since the nut and axle were in exactly the same position, the axle must have stretched.

The proper proceedure for the axle issue is not to go to town and keep tightening the nut everytime its loose. This keeps weakening the axle until it snaps right at the base of the spindle. I put in a 4th axle and this time used red lock-tite and TQ'ed it to 100ft pounds. It isnt comming off and its not tight enough to stress the spindle. Since my first axle's nut actually came off and I didnt know it while driving around for countless miles, it is obvious that the axle nut doesnt have to be there for the axle to stay in place so tight isnt the answer. The red lcoktite will keep it from ever comming off and the lesser TQ value will never affect the car's performance or safety.

For those that have a fear that the nut is dangerous if its not to 100+ft lbs, imagine the tragedy that would occur if the axle breaks on the hiway and whips around taking out control arms and such. YThats a bad place to weaken an axle and TQing it to higher and higher values with such a tensile stress will eventually result in a failure. Do not keep TQ'ing that nut. Lock-tite it and leave it alone. If it isnt off, its doing its job wether its lock-tited on at 118 or 50ft pounds.

To date this issue has cost me about 1400 bucks. 3 replacement axles and the hub has the sensor for the active handling/brakes sensor in it and one of the breaks took out the wire to it. The current axle has been on for about 5000 miles and they are pretty hard miles......600rwtq (nitrous car) with race compound tires that stick all that power on the launch with it being a Z51 and with 4.10 gears. It works this way. The nuts are fine marked and not moving, nor are they loose. I cant check the value sicne it would break the lock tite grip but its not comming off, nor is it being retq'ed all the time.

Replace the axles with the one from the C5.

 

A second set of nuts added after torquing the first set works too. I have put 10,000 miles on mine with no movement.

 

Makes sense to me.

 

True story. Four months ago my 2005 began a whinning sound from the rear of the car. My dealer diagonised it as differential carrier bearings, and replaced the entire differential with a new one. Noise persisted and I asked the tech if he had checked the torque on the axle retaining nuts. He said that this was a Z06-specific problem and had not checked them. We pulled the center caps from the wheels and the LH side was at 26 pounds, and the RH side was at 8 pounds, and had destroyed the bearing races. It was repaired and I've had zero issues since..................... but I think I will recheck them this weekend.

 

Read all the posts, thanks for the head's up !!! Decided to check my torque's 2008 3lt Z51 10,000 miles. Drivers side 100 # Passenger side 40# Re-torqued to 118 as stated in prior posts, marked nut and shaft with witness paint. Checked the Shop Manual page 7-157 Correct torque 151# 2008 specs may be different check yours !!!!!!!! Took 3 min to re-torque and re-paint marks

Tool; Performance Tool pn W80553 33mm Deep Wall 1/2" drive $9.99 O'Reilly Auto Parts Garland TX

Loose axle nuts and loose lug nuts I wouldn't trust on my wheel borrow, Glad I checked it out !
Harry House
Garland TX

 

If over-torqing the axle nuts and stretching the axles until they break is the problem, why did GM issue a technical bulletin to increase the torque to 160 ft-lbs?

 

I also have read all posts. Thanks to all for the heads-up for me.

I had a 36 mm socket for my prior 1994 Corvette axle nut ... naturally it was way too big (I was thiking that maybe GM would have stayed with the same size, but now realize how different the suspension really is between the two).

So I ran to Northern tool tonight for a 1 5/16 socket and a 3/4 to 1/2 adapter. Total cost around fifteen bucks. Fit perfect. Driver side needed almost half of a turn to get to 118. The passenger side took less than a quarter turn. My 2005 has 30K on it and even though I just got it from the original owner, I'm pretty sure this was never checked before.

I saw something in one post about GM changing the spec from 118 ft lbs to 160. Are folks confusing 160 N-m with ft lbs? Because 160 N-m equals 118 ft lbs.

One question about the double nut solution. Wouldn't any nut of the same ID and thread pattern work? Just wondering if the local hardware store might have something that would work since the second nut is just holding the "real" nut from moving???

 

The one I read said to lock-tite and go to 118. Both of my axles snapped at 118 after multiple tightenings. Do what you want. I'm just sharing my experience and you dont have to follow it.

By the way, I lost count on the mistakes GM made; delaminating tops and balancer pulley's falling off the car. The latter, they wouldnt admit to being an issue for a year until they did a recall and installed a washer in the chain. And how about them weak 2005 diffs that they refuse to swap out for a stronger one that was changed in 2006 to the stronger unit? Knowing its a weak point the dealer wont put in the 2006+ unit...they give you a 2005 unit and figure theyre done with you when your warranty is over. They cant figure out the gas tank problem regardless of how many trips back to them and 3 bulletins on how to fix it.

Next up is the column lock fiasco of the C5 days. There wasnt a recall on that sucker for 3 years. How long until someone's steering wheel would have locked while driving....oh yeah it did happen to Neptunebill.

I dont put much faith in GM's fixes. I'm not selling anything to you. I am telling you about 3 factual axles, what I did and how I fixed it. If you think the right answer is to keep going to higher and higher TQ values when the nut isnt turning, do what you want. Crushing things down even more makes no sense to me. You have the same axle so the value isnt different. For the record, the correct answert is less TQ and a retaining/cotter pin to keep the nut from turning. Even Toyota figured that one out. Having it stretch and lossen to 40ft pounds but being lock-tited in place is the safest thing to do, not over tighten in and risk a break on the hiway and have a swinging axle take out your rear wheel suspension at 70 mph. If the nut isnt spinning, it isnt unsafe.

I was 130 miles from home when the 2nd one broke. Forum member Aintqik gave me his axle to get home.

 

Spin, thanks for the info. I must have missed your previous post regarding this. All makes sense.

So then the question I'd have, what is the "lowest" acceptable torque value for the nut and how do we keep the torque from dropping below that value? Loctite or double-nutting will keep the nuts in place, but how do we keep the torque where it needs to be?

If we tighten to 118 ft-lbs, Loctite and then just leave alone, eventually the torque will become less as the axle stretches... the nut will not come off because it's Loctited so that's good... but finally, when will the axle shaft relationship become "too loose"?

As Eurorod mentioned, his torque was 26 ft-lbs and 8 ft-lbs and the bearing races got damaged... perhaps in a perfect world, the torque would be say no less than 50 ft-lbs at all times (with nut Loctited to keep it from loosening), but if we Loctite the nut, we cannot easily check the torque and over time the torque may drop "too low". Just discussing here.

Or maybe we'd need to torque to say 50 ft-lbs, Loctite the nut, and then periodically crack the nut free, clean off the old Loctite, add fresh Loctite and retorque to 50 ft-lbs again... just to make sure the torque is not too far below 50 ft-lbs... because eventually, I suppose if not checked, the torque might drop to near zero... and perhaps that's not good.

Or, would you say that if torqued to just 50 ft-lbs, perhaps the axle just would just not stretch....? No enough torque to stretch it...? (Unless the axles deform in all directions from hard drag race use...?)

I wonder how much of all this is related to adding extra stress on the axles from drag race use? I'd think that if these axles are stretching so much just from 118 ft-lbs of torque on the nuts, they'd surely have to stretch / deform a whole lot under the stress of a hard drag race launch... I'd think there's a whole lot more torque going on here, granted, in a different direction, but extremely high amounts of torque regardless.

So Spin, I have now just checked and adjusted my axle nut torque to about 118 ft-lbs... no Loctite... so what you recommend perhaps is that I just leave everything alone now and do NOT retorque anymore and just make sure the nuts don't fall off...? I could remove the nuts now and reinstall with Loctite, but being that they're torqued nice right now, I'd rather just leave them alone, no need to remove and reinstall right now, that only serves to un-stretch and re-stretch the axles, they don't need that.

Here's an idea... Spin, what do you think of this... perhaps double-nut (instead of Loctite), set the main nut to say 50 ft-lbs, then add second "lock-nut"... then periodically remove the "lock-nut" and check / retorque the main nut to just 50 ft-lbs... double-nutting allows for easy retorquing without having to clean off old Loctite residue, etc... and torquing to just 50 ft-lbs (instead of 118) should hopefully not be enough torque to damage the axles.... gee, if they can't take 50 ft-lbs of axle nut torque, they really should not be on the car at all. This method will allow the torque value to be maintained at close to 50 ft-lbs at almost all times, at least if checked often enough...

But if we "set and forget" using Loctite, who knows where the torque value will drop down to over time... and "too low" might not be a good thing.

Anyway, just ideas, food for thought....

 

 

Locktite and marking the alignment of nut to axle won't work if the reduced torque is due to anything other than the nut backing off.

I think double nutting would work if an axle nut similar to the one in the pic that is self locking and holds torque would work. In other words torque the original nut to spec and torque this nut as a second nut against the original nut. The original nut can't back out and if it ends up loose something else is going on besides nut movement.

The nut in the picture (p/n 10289657) is from the front axle of an N car and serves the same purpose as the nut discussed here.

 

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

 

Axle nut problem: This is what I did 9K miles ago and they have not loosened up since. You'll need a 33 mm and a 34 mm 1/2 " drive socket as the hex on the nuts are not consistant. Torque the nut on the axle to 118 lb-ft. Clean the area where the nut is located and the threads on the axle with a small wire brush. A second nut PN# 10257766 $9.35 from your dealer is required. Torque this nut to 100 lb-ft. Brush some primer on the nuts, axle threads and the surrounding area to prevent future corrosion. When the primer is dry, use a contrasting paint pen to mark the exposed axle threads and the face of the 2nd nut with a line. This will allow a quick visual when you pop the center cap on your wheel the next time. Repeat this process on your other rear wheel. Good luck.

 

pictures?

 

The rear axles on my car were fine to the day I went to cartek and they were loose as per their mechanic who tightened them to 150ftlbs and it broke that same day. Next axle in 150ft lbs and it broke the same day I picked it up. Meeting at cartek: nut is overtorqued so lock-tite and dont go to 150.....keep it at 100. They paid for the replacement and it never broke again.

Result.....5k miles with a nitrous car and sticky tires handling 600rwtq with 4.10's and Z51 gears....no breaks.

160ft lbs is too much. Why isnt it breaking with the guys that do it? Clearly the TQ multiple on my car is higher but if a guy breaks 2 axles with the higher 150 tq value and doesnt break at 100ft pounds and lock tite, I would follow the latter path. Maybe if a few of the happy TQ wrench guys who keep tightening it every few 1000, raise their power a bit, they will see for themselves. Until then, dont put much faith in GM bulletins intended for cars with 350rwtq and 3.42 gears with TQ management. Modded cars need a more sensible approach and will be best served by not ignoring people's findings with more power and failures. GM has and will be wrong on this and future issues.