Torque Limiting Stick for Wheel Lugs ?

[oragex]

The thing with the wheel lugs is that the surface of the wheel where the lugs sit against, gets corroded and rough causing the torque reading to be wrong. I'd make sure that surface is clean and shiny first.

[j-dawg]

I am aware he is overtightening. I do not have a problem with it since I lubricate my lug nuts and he said he's had problems at min. torque.

Sounds like you've been doing this a while without problems, but it's worth noting that a lubricated bolt is going to snap with less torque than an unlubricated bolt. Not sure how Volvo intended them to be with regards to lubrication, but I've always tightened mine to 80 lb ft dry and never had one back out. Used to live deep in the Rust Belt and I never had a wheel fastener seize.

The lube-or-no conversation has been had a thousand times and nobody's snapping bolts left and right, so I'm sure what you're doing is fine, but I thought I'd mention it.

[E Showell]

Got tired of the puffs of smoke and rifle crack sound coming from dry lug bolts when loosened.

[PeteB]

I've seen pros say that wheel lugs should be dry, and that they've seen/heard of
cases where wheels fell off that had lubrication.
I also put anti-seize on for many years, but don't do it anymore.

[abscate]

Yeah, that debate rages in full atomic mode on car fora.

I use never seize on all lug nuts and torqued by feel for most of my life. I used a wrench to get a estimate of where I was torquing then and I turned out to be 60 ft lbs or so. That was kind of nice as the estimates I read for reducing for lube is 30%.

I've also never had problems with lug nuts coming loose

[mecheng]

I've designed fastener systems as an Engineer so I can offer some insight:

Reasons why I lubricate the threads. Actually, every fastener I remove on the car, I use anti-seize.

1)Fatigue life of a corroded faster is min 50% of a non corroded faster. MIN is key word!!! Source: fatigue theory: Machine Design.

2)I've never heard of an Engineer designing a system assuming dry torque, they know mechanics don't work in a clean room and therefore they size the bolt appropriately.

3)Lubricated threads provide greater clamping power and due to point 2) they are well below the yeild of the bolt.
Not convinced, do a calculation using the bolt equation T=kfd, you will see 110Nm is nothing for a Volvo lug nut on these specific cars.

4)With enough salt and no lubrication, fasteners do seize with time. I've seen it many times. One day it will haunt you.

It is an endless discussion only because there is so much miss information.

[PeteB]

Thanks very much, great info, and that was basically my intuitive thinking all along
from back when I _did_ use lube, so perhaps I'll go back to using it.

Thread damage/corrosion is why I went back and used new bolts for the front struts
and caliper mounts. The threads looked bad so I used new per the factory manual.

[abscate]

Heres my thoughts ..fwiw.

Are you over torquing if you use 80 ft lbs with lube? Yes.

Does it matter? No.

The three places that contribute to torque are
Friction of fastener to surface
Friction of threads
Deformation of fastener

So, lube reduces the first two and puts more of the torque in the last one. In short, I don't think a typical lug tor stud suffers much deformation between 60-100 ft lbs of torque, so all is well.

Of course, lube in the salt belts means you have a shot at getting them off without a McGilla Gorilla