Grease on wheel nuts???

I suspect there will be a number of differing opinions on this....!

FWIW, one of the first things I do with a new car is remove the wheel nuts, lightly coat the threads and mating faces with Copaslip, then tighten them with a torque wrench. I've been doing this for over 30 years, have *never* had a nut come loose and have *never* been unable to remove a wheel in an emergency.

BTW, don't use ordinary grease, wheels get very hot and the result will be messy wheels and not much grease where it's needed.

HTH

Chris

The industry standard guidelines (BSsomethingorother), states that the wheel/hub mounting surfaces and wheel nuts/studs should be free from paint/rust and given a coat off light oil(ie engine oil) during installation. The use off grease is not recommended.

The thinking behind it is, if you use grease, when you initially tighten the wheel, the grease creates a layer between the wheel and hub, which as soon as the hub/wheel warms up the grease will thin out and gradually move from between the wheel/hub resulting in the wheel loosening off. The oil doesn't have the same effect, and is forced out as soon as the wheel is tightened.

Also, grease on the nuts/studs can cause them to drag when tightened resulting in the wheels not being tightened properly.

Maybe not, but same as Chris, I've always used Copperslip on wheel bolt/nut threads, and head seatings, and never had any trouble removing them or had any come loose.

I think that is complete nonsense as far as wheel nuts/bolts are concerned. On large areas it's a valid point, but over small areas like those on nuts and bolts, I don't think it's even worth considering. A light smear of Copperslip ensures you wont be stuck at the side of the road with a puncture, unable to change the wheel because the supplied wheelbrace is not man enough to undo the wheel nuts. Mike.

if the wheel nuts are torqued to the correct tightness and not done up by some monkey keeping his finger pressed on the air gun till all the air has run out of the compressor, then you shouldn't have any problems undoing the wheel nuts with the supplied wheelbrace.

ive never or had the need to put any kind of grease or releasing agent on wheel nuts, the only time I use a small amount of copperslip is where the wheels go onto the hub, especially with ally wheels as they corrode against the hub & ive had wheels where ive had to literally beat them off with a plastic dum dum hammer as they wont shift with corrosion.

Obviously opinions are divided. From the POV of retaining the wheel, I don't think Copperslip increases the chances of wheel nuts coming loose, which seems to be the main objection against it's use. In the end it just comes down to personal choice IMO. Mike.

The message from "LittleBro" contains these words:

Yes and no. I use copper grease which was created for just this sort of thing.

" The bolt threads should be clean and free of rust. While it helps to lubricate the threads with light penetrating oil, never use a lubricant that leaves a heavy oil film or that contains a friction modifier. Friction modifiers reduce the friction between the wheel nut and bolt and cause false torque readings."

Wheel bolts or studs are vastly over specified - they *have* to be for the average tyre changing monkey. So the extra tension produced with a greased one being torqued to the correct setting is neither here nor there.

And I'm definitely in the use copper grease camp. And on the back of alloy wheels.

Ok just to keep this thread going :-) isn't copperGrease XYZ for use where heat is involved eg exhaust manifold nuts? Why Cu grease rather than non-Cu for wheel nuts?

An interesting point. Of course copper based grease is also promoted as an anti-sieze grease, which possibly makes it a little more suitable for wheel nuts, where it's possibly better than ordinary grease at preventing a pickup on the mating tapers. Also wheel hubs can get quite hot, so maybe a copper based grease is less likely to melt away. Dunno really. I'm just fishing for reasons. Maybe someone has a more scientifically based one.:-) Mike.

The message from dave contains these words:

Copper grease is for anywhere [1] where threads might seize. It works well on threads which get hot, but it also works just fine on threads which don't.

Wheels, of course, can get quite hot!

Copper Based greases are fine for heat based applications as the copper particles suspended in the grease helps to dissepate the heat to other surfaces which helps the grease to remain a solid.

One word of warning though, dont be tempted to use it on valve stems when assembling cyinder heads. I've witnessed it seize the valve into the valve guide by stopping the engine oil getting to the valve.

DJ_Crazy_Frog

The message from DJ_Crazy_Frog contains these words:

What on earth are you on about? If two bits of metal are at n°C then the film of grease between 'em is going to be a n°C too. There's nowhere for the heat to go to that isn't already at the same temperature.

The copper is there because it's a soft metal which forms a fine film over the surface of the threads. You'll find the threads of things like G-cramps are often copper plated for the same reasons.

It should never be used as a substitute for a lubricant. It's an anti-seize compound - that's all.

I think you need to check that statement.

Are there no limits to the mistakes mechanical wallies can make? Don't they even bother to read the labels on products. Mike.

The message from "Mike G" contains these words:

Apparently people have been known to use it on clutch release bearings. There are dire warnings in the packet about not being covered by the guarantee if they find copper dust in the balls.

I imagine there is. It sounds quite painful. Mike.

We use it in the hospital to stop the bolts holding the head of our linear accelerators from sticking. The heads weigh around 1/2 tonne and have to be removed annually (fortunately, only annually) to check the components behind for wear. As you've got patients underneath, these bolts are tightened fairly firmly so you don't want them to sieze. Neither can you use a normal grease because the high levels of radiation would cause the grease to solidify. Cu grease is ideal because it won't congeal, it forms a low friction film.

^^^ You have never owned many cars where the wheelbrace has been the last thing on the designers mind then.... Have a look at a Fiat Coupe or Citroen Xantia and tell me if you think they were well designed....