No grease on lug nuts

Never grease lug nuts. It causes over tightening that leads to warped rotors.

a definite and absolute NO. Never put grease or oil on them.

A wet torque is better than a dry torque. If the lug nuts on a car are supposed to have a torque of 75 ft lb, how does applying grease make you torque them to more than 75 ft lb?!?! Get grease in your eye and can't see the dial, or get it on your hand and slip off before you hear the click?!?! Please, what are your suggestions for anti-seize, WD40, CRC and oil. Penetrating oil allowed?!?! So, when I put oil on my squeaky wheel barrel tire, I ?m actually tightening it?!?!

I disagree. We were taught in FoMoCo classes to never oil, grease, or antisieze nuts and bolts without specific instructions from the mfg to do so. Yes, the torque is the same but the stretch is different. Your wheel barrel does not have disk brakes that often run very hot.

Errr..it doesn't force you to do anything, but a 75 ft-lb "wet" torque will generate a higher tensile value in the male fastener than will a "dry" torque of 75 ft-lb.

The torque reading is simply a measure of the frictional resistance to tightening the fasteners. Various combinations of dry, lube, plating, all give different torque-tensile relationships.

Doesn't quite work like that.

Unless otherwise 'specifically' stated, all torques are given for dry components.

The difference can be the bolt being rally tight with the proper dry torque to actually snapping with a wet torque.

If you want to mix, there are charts around for the equivalent wet to dry torque for clamping force. Something like a 60% difference.

Mike

Well, that concept is horseshit...

You dont use grease because the specifications are made of clean dry threads, and you will exceed the acceptable tension of the bolt if you use grease without compensating in torque readings.

IF you compensate by decreasing the torque for greased threads, then you can get the same, or nearly the same bolt stretch (tension) by using greased bolt threads. This is the true clamping force.

I have never seen a bolt loosen which has been properly torqued in the first place, whether lubricated or not. If this were the case, you couldnt keep connecting rod bolts tight.

That is a myth, an old mechanics tale, BS.

So, what about greasing the face of the nut, where it presses against the wheel?

The contact between those two friction surfaces creates some of the torque. To get the same 100 ft lbs, the nut will have to be turned more creating more stress and stretch.

If you can measure bolt elongation (and you can), you can attain the required clamping force irrespective of the observed torque..

Torque in foot pounds is only relevant if the condition of the threads and the friction between the bolt face and metal surface are within the bounds which the engineer intended. (A nut that is a few thousandths of an inch narrower in bore or wider will also affect this.)

This does not mean that you cannot grease the threads and achieve a perfectly useful clamping force, but you will not do it at the same observed torque that you did with dry threads.

Some years ago, I searched the internet and found the concensus that to use greased threads, you need to drop the torque figures by about 20-25 percent. I have no idea whether this is valid or not.

I never grease (or oil either) lug nuts.Put them on there dry. cuhulin

ONLY time to grease is if specs SPECIFICALLY call for it. Default torque is dry.

Pete

With stuff like Nevr-Seize, the applied torque needs to drop to something like 45% of the dry torque. It's pretty slippery stuff. The manufacturer gives the torque for "clean, dry threads." The problem is that a car that isn't new doesn't have clean threads, nor are the nut and wheel bolt cones nice and smooth anymore. Rust and the normal bit of tearing of mating surfaces in the threads and cones will result in less tension in the stud for the clean-dry torque. The cad plating also wears or corrodes away. On my ancient IHC pickup I use a tiny bit of Nevr-Seize on the stud threads, since they're getting rougher as the years go by. Dry threads that are rough will soon enough weld themselves solid and you'll strip everything or break the stud trying to get the nut off.

Dan

I think you and I are more or less on the same page. I would prefer to use a little Never Seize than to have nuts stuck to studs. I derate. I have NEVER had a problem. A lot of this is pedantic BS. There is NO reason not to use Never Seize or similar so long as you derate the torque. Now, how much should you derate?? Either buy yourself a bolt elongation gauge, or derate 25% plus/minus, or just stick with your torque ratings and give your rusty threads a bolt enema.

Reasonable people do what works. And sometimes this requires some R&D.

That is a good boy, cuhulin

We have all agreed to this many times over. It is not the only answer but it is the answer for people who want simple answers.

I never grease my nuts either.

I just don't see how it makes any sense at all to lube the lug nuts.In my opinion, almost nobody does that.There are a million and one bolts and nuts and other kinds of fasteners holding those buckets of bolts (cars) together.Why lube the lug nuts? cuhulin

It is helpful if you live in a place where salt is used on the roads, and where corrosion is particularly rough. Lug nuts can freeze on the studs. You can twist off the studs trying to remove the nuts. But I guess that is not an issue where you are from.

A little antiseize or grease can help a lot. But you have to consider that you MUST reduce the torque if you are going to do this...

Does that explain it?