Retorquing the lugs

[C-MaxJaxon]

Some of you may be aware of the tire shops that make you sign some kind of agreement to retorque the lugs on alloy wheels after 50-100 miles. I would guess most people don't ever do it, but I usually do check them with a socket and snug them down because they need it.

 

I checked the lugs on my C-Max and when I got to the rear passenger wheel, the socket didn't fit onto the lugs very wheel. And, clumsy oaf that I am, I rounded off one pretty badly and another slightly. It's odd that only one wheel had the problem. It appears that those lugs are slightly bigger, maybe 3/4" instead of 19mm like on the other wheels. Just wanted to warn others and see if anyone else had a similar problem.

[Seymour_Bears]

Just checked mine - all the lugs nuts are 19MM.

[marshtex2]

A tire shop did a screw hole repair (wouldn't plug it) and slammed the lug nuts home with an air wrench.  I complained to the mgr about not using a torque wrench by hand.  So I want to do that but can't find lug nut torque specs in the manual.  Anyone seen a spec. on that?  I suspect around 70 to 80 ft lbs.

[mtb9153]

A tire shop did a screw hole repair (wouldn't plug it) and slammed the lug nuts home with an air wrench.  I complained to the mgr about not using a torque wrench by hand.  So I want to do that but can't find lug nut torque specs in the manual.  Anyone seen a spec. on that?  I suspect around 70 to 80 ft lbs.

I have replaced the factory lug nuts with racing style longer red anodized nuts with open ends allowing you to see the end of the threaded stud inside the nut.  Why you might ask?  For looks mostly, they look cool in my opinion.  I have told my dealership when they to the visual inspection of the tires and brakes, too not re-torque the nuts with an air wrench because the manufacturer of these nuts says not to air torque them.  But the dealer still has done it which pisses me off.  I recently bought new racing style nuts with a hard red anodize coating so they don't fade from the sun like my cheaper first set did.  The old ones were on so hard that I thought I'd never break them loose because they got galled up in the aluminum by over torquing them.  So I applied bearing grease to minimize this in the future. 

Edited October 14, 2013 by mtb9153

[JAZ]

Page 349 of the Owners Manual 3rd printing recommends 100 ft lb torque.  As for lubing the lug nuts, opinions vary, but from a Corvette forum:

 

 

 

Discussion: I've worked on several bolt torquing issues & systems for GM over the years. Any applied torque is meant to establish a 'desired' tension value in the stud/bolt; this translates to an amount of stretch in the bolt. That applied stress needs to be below the permanent deformation strength of the stud/bolt, or it will permanently stretch and lose torque and retention. Too much, and the stud/bolt snaps. So, if you lube the threads or the joint, the same applied bolt torque will result in higher strain/stretch in the stud/bolt. If it doesn't exceed plastic deformation levels...no harm done. If it does, but doesn't exceed permanent deformation levels, the stud doesn't snap, but it does lose strength and bolt retention. The stud/bolt can snap, if the torque level is high enough and quick enough.

Bottom line: A little anti-sieze on the stud threads will probably not snap the stud if the correct torque is applied in the normal manner. If an overpowered air gun is used, the stud will likely snap before the nut/driver ever slows down.

 

 

 

[ceemax71]

Page 349 of the Owners Manual 3rd printing recommends 100 ft lb torque.  As for lubing the lug nuts, opinions vary, but from a Corvette forum:

 

 

 

Discussion: I've worked on several bolt torquing issues & systems for GM over the years. Any applied torque is meant to establish a 'desired' tension value in the stud/bolt; this translates to an amount of stretch in the bolt. That applied stress needs to be below the permanent deformation strength of the stud/bolt, or it will permanently stretch and lose torque and retention. Too much, and the stud/bolt snaps. So, if you lube the threads or the joint, the same applied bolt torque will result in higher strain/stretch in the stud/bolt. If it doesn't exceed plastic deformation levels...no harm done. If it does, but doesn't exceed permanent deformation levels, the stud doesn't snap, but it does lose strength and bolt retention. The stud/bolt can snap, if the torque level is high enough and quick enough.

 

Bottom line: A little anti-sieze on the stud threads will probably not snap the stud if the correct torque is applied in the normal manner. If an overpowered air gun is used, the stud will likely snap before the nut/driver ever slows down.

 

 

 

 

Good post. 

 

The shop manual says NOT to lubricate the wheel studs or wheel nuts:

 

NOTICE: Make sure to apply a thin coat of anti-seize lubrication only to the interface between the wheel pilot bore and the hub pilot.

Do not allow the anti-seize to make contact with the wheel-to-brake disc/drum mounting surface, wheel studs, wheel nuts, brake pads or brake disc friction surfaces or damage to components may occur.

[marshtex2]

JAZ, thank you for the referrence, page 349 in the manual.  I thought it should be there but couldn't locate it.  More another time on the cleanliness/lube issues with torqueing.