ncnmra

I'm going to be replacing my axle nuts in an attempt to address a rear end clunking. I've read dozens of threads on the replacement procedure, but each one discusses different torque specs. I've seen anywhere from 118, 120, 140, 151, 160 lb-ft.

I read some stories of axles breaking after new nuts being applied, and theories that the 160 lb-ft is for new axles, but old ones that are pre-stretched should use a lower torque. Given the use of Red Loctite, I feel like this is a one shot thing, so I want to get it right, without breaking them.

Car is a 2008 C6 Z06 with what I can tell are stock Axles. I'm tempted to "split the difference" at 140 lb-ft.

What's the final verdict?

Scotthmt

Sent it on with a pneumatic impact 🤷. Clunking can be from the sway bar tie rods.

92rsz

Clunking from the rear besides the sway bar links can also be cause by rust between the axle splines and the hubs. My 08 did it. Very noticeable when pulling forward after reversing. Pulled the axles out of the hubs and greased them 4 years ago. The noise hasn't returned. I torqued the nuts on mine to 150 lb ft

eagle7175

118 lb-ft, 34mm socket is what i use... 2007 Z06

ncnmra

Yep, I plan to do that while the nuts are off. What kind of grease do you use? This is also one of those "many answers" where I've seen Penetrating oil, WD40, Lithium Grease, etc. I have some high temp axle grease that I use on my trailer so tempted to go that route.

ncnmra

I'm leaning to the side of 120. However, the TSB # 07-04-95-001 states 160lb-ft, but I've read of guys with broken axles afterwards.

https://www.corvetteforum.com/forums...-bulletin.html

Aardwolf

I have both a 33 and 34 mm socket and the 33 fits much better. Your high temp axle grease sounds made for this.

92rsz

I used moly grease on mine, but I think anything that will keep the splines lubed is better than nothing

ncnmra

Good reminder.....I think I have some of that for the splines on my Jetboat. Is there enough room to get the grease into the splines when the nut is off? I've read of people pushing the axle in a ways to get extra grease in there. Also, I'm presuming the lubrication is done on the hub side, not the diff side, correct?

92rsz

You might be able to get a little bit in there with the nut off, but this pic will show you why I had to pull the axle out of the hub to wire brush off the rust. Yours will likely look the same

ncnmra

Oh boy....This job is escalating, but I don't like to take shortcuts. What did you have to remove to get the hub off? Looks like caliper and upper A-Arm bolt? Was there enough room/angle to then slide the axle shaft out from the hub?

92rsz

Yep, caliper, upper control arm, toe link are disconnected and you can wiggle it out of the hub with a few choice words lol

Blizzard1975

As many others, I use two nuts per axle. Won’t come off.

ncnmra

How much do you torque the second nut?

Blizzard1975

GM spec

Lights ZR1

As of May 2023 the axle nut torque spec is 151 ft lbs of torque

gsflyer2011

This. 120 is too low, 160 is too much. Instead of going through all that trouble, first spray lot of WD40 on the spline, and retorque you bolts initially and after few cycles, see if that stops the clunking. If it does not it is something else.

Dj_or_dj

one sec

let me see what the tech manual says

Dj_or_dj

ncnmra

I'll do the job in the next few days, but last night I went to check with a torque wrench set to 110ft-lbs. The driver's side was fine, but the passenger side moved about 1/4 turn before clicking in. I went for a drive and the clunk was completely gone, so I can safely say this was the issue, even at a low 110ft-lbs setting. It was like driving a totally different car, I didn't realize how much that clunk annoyed me.

@Dj_or_dj : Do you know if the spec changed for 2008+? I read somewhere that GM updated specs for that year. I also read that the TSB recommendation of 160lb-ft was on "wet" threads due to the Loctite.

Given that the issue was solved at 110lb-ft, I'm certainly leaning to less than 160. Last thing I want is a borked axle.