Wheels Bolts - Leave Dry Or Grease Em?

[erbs 42 1 Cars]

I use ms3 grease on my car and on my transit graphite stays wet and designed for heat and when I need to take a wheel off like I did on my transit the other day, I loosened the nut then just spun the nut off with the brace nice and easy

 

Always grease threads in my opinion, only way to ensure that they don't seize

 

I have never had a wheel come loose and the chances of one of the wheels coming loose without me noticing are pretty slim

[kenp 3]

Copperslip and always torque the bolts up. Especially important if you run a comp car and change wheel a lot.

 

For a road car, a smear of Copperslip on hub face will help prevent the wheels sticking on.

[petert 586]

Could someone who said "NO" to using coppper coat on wheelbolts, tell me where it is ok to use copper coat on a car?

[dobboy 231 2 Cars]

PeterT, this is from a copper ease data sheet. (I think it is ok to use on wheel bolts, but if you don't want alloys to corrode it's best avoid contact with the alu.

 

 

APPLICATION

• An anti-seize assembly compound that is copper based with an extreme temperature range.

PROPERTIES

• Provides excellent protection for metal parts against seizure, corrosion, heat, rust, acid and water.

• Improves sealing and eases assembly and dismantling of:-

Cylinder head gaskets and bolts

Gaskets of all descriptions

Steering and suspension

Universal joints

Spark plugs

Nuts and bolts

Exhaust systems

• Helps prevent disc brake squeal.

[GLPoomobile 958]

This thread has turned out to be quite interesting.

 

This all kicked off on another forum I use, and I posted the question here because I respect the mechanical and engineering prowess of a number of our members. I'd never considered it before, as I always grease my wheel bolts and tighten by feel. I've used copper slip in the past but reverted to normal grease as I found the copper slip dried and was a bit more resistant to undoing (in hindsight, that property would be preferable and it's embarrassing that I didn't even think of that at the time). Without knowing, or even considering some of the engineering reasons for why wheel bolts should be treated in a certain way, I've been stuck in the mindset that I just want my bolts to go in smoothly with no risk of cross threading, and more importantly, I want the buggers to come undone again when I need to remove a wheel! Since I've never had a wheel bolt come loose before, I've never considered the risk of this happening due to using the wrong techniques!

 

So what I've heard (across both forums) is that:

1 - Using grease changes the torque being applied and could result in over-torquing

2 - Putting them in dry could lead to hitting peak torque before clamping force is reached

3 - Correct torque is required as it's the face of the bolt against the wheel that provides the clamping force. If the clamping force isn't reached, because the correct torque has not been applied, then the bolt could work loose

4 - Don't use grease between the mounting face of the hub and the back of the wheel. It's the friction between these surfaces that helps spread the rotational load of accelerating/braking. If the mounting face is greased then friction is reduced and more of the rotational force is transferred to the bolts. Only the spigot should be greased to prevent the wheel seizing on the hub.

 

So from the above, what I've taken away from this is to thoroughly clean both the bolts and the hub threads (obvious), use copper grease but only apply a bare minimum smear to the first 2-3 threads of the bolt (never get grease on the bolt face, and don't use so much that the grease squeezes back and out over the bolt face as you wind it in), and to do the bolts up to the correct torque. But that last bit is still a bone of contention as how do you know the correct torque if the grease is affecting that? Since I've never had a bolt work loose, I shall probably use a torque wrench as a guide but ultimately rely on feel, as I've always done.

[johniban 59 1 Cars]

Could someone who said "NO" to using coppper coat on wheelbolts, tell me where it is ok to use copper coat on a car?

 

Copper coat, is this the same as copper grease? i use it on the shoulders of head bolts, not on the threads, brake pads (most pads comes with some kind of copper or graphite grease) when i remove wheels i clean up the hub flange face and inner of the wheel and apply a thin smere of copper grease,on rear drum brakes where each shoe has 3 contact points with the back plate,

[johniban 59 1 Cars]

 

 

So what I've heard (across both forums) is that:

1 - Using grease changes the torque being applied and could result in over-torquing

2 - Putting them in dry could lead to hitting peak torque before clamping force is reached

3 - Correct torque is required as it's the face of the bolt against the wheel that provides the clamping force. If the clamping force isn't reached, because the correct torque has not been applied, then the bolt could work loose

4 - Don't use grease between the mounting face of the hub and the back of the wheel. It's the friction between these surfaces that helps spread the rotational load of accelerating/braking. If the mounting face is greased then friction is reduced and more of the rotational force is transferred to the bolts. Only the spigot should be greased to prevent the wheel seizing on the hub.

 

 

 

my answer to 1 and 2 of your points are: if these were true then the manufacturing process used and governed by safety tests ect would im sure have something to say about that? why does no new car that rolls off the production line come with grease on the wheel bolts if this is true?

 

hitting peak torque before clamping force is reached would indicate damaged threads, rusty threads or wrong threads. there is no reason to grease a wheel bolt at all in my opinion but im not an automotive engineer or work for nasa or a scientist so i cant really explain the law of physics.

 

i kind of agree to the last point but its been in most service sheets on prestige brands todo on servicing, ( on mercedes-benz vehicles over 12 months old it is) you try explaining to an 80 year old why he cant get his wheel off at the side of the road with out a rubber mallet

[dcc 855]

I have always put a small dab of heat resistant grease on a wheel bolt, or even any regularly used bolt. I have had to change gearbox 3l2 or 4 times on my car, at no point have I had an issue with any bolts not being tight. Certain bolts require thread locking compound, other do not, but the most important thing to remember is correct torque and bolt types. What amazes me is the number of people who over tighten bolts because they thibk they take a lot of loads... Case in point my girlfriends golf. It recently had new tyres, the pillock at the tyre place whipped them up with an aitgun and made sure they were atleast at the setting on his torque wrench. I cannot stress how dangerous this was and the severity of the situation it left my girlfriend in. 3 bolts fell out of 1 wheel and 5 bolts were on last few threads of other wheel. The reason being that the bolts were over tightened. None of them had any grease or slip applied. If 1 bolt is near 110nm but yet 1 is near 220nm, the others somewhere in between, you end up with effectively just 1 bolt clamping the wheel to the hub flange.

 

I then retorqued the bolts after her car was recovered and applied a dab of grease. Torqued the bolts up to correct setting. Funny enough 4-5weeks pass with no issues. I checked the torque last time I went home to see her and they are all bang on.

 

I think people need to understand the meaning of torque, work and friction before wandering off on too much of a tangent.

 

The main issue I have personally found with copper slip is it dries as mentioned, leaving a horrible build up of copper or god knows what else. The most common being the sliders of brake calipers. I have worked on a car where somebody put it on every bloody bolt they could find. Made the threads very tight and a bloody hell of a mess.

[johniban 59 1 Cars]

I just torque wheels up as everyone else does at that place I work it's a prestige brand and we all work to the manufactures guide and use their torque settings provided, year after year we work on the same cars and never have had a problem with wheel bolts, never used grease or seen anyone use grease, just a torque wrench (that's calibrated every 6 months )

[GLPoomobile 958]

 

my answer to 1 and 2 of your points are: if these were true then the manufacturing process used and governed by safety tests ect would im sure have something to say about that? why does no new car that rolls off the production line come with grease on the wheel bolts if this is true?

 

hitting peak torque before clamping force is reached would indicate damaged threads, rusty threads or wrong threads. there is no reason to grease a wheel bolt at all in my opinion but im not an automotive engineer or work for nasa or a scientist so i cant really explain the law of physics.

 

i kind of agree to the last point but its been in most service sheets on prestige brands todo on servicing, ( on mercedes-benz vehicles over 12 months old it is) you try explaining to an 80 year old why he cant get his wheel off at the side of the road with out a rubber mallet

 

With regards to your first comment, I suppose that on a brand new car with everything spanky clean and shiny, there's simply no need to grease up the wheel bolts. But also, they have an obligation to ensure the car is safe and reliable, and if using no grease and ensuring that the exact torque is applied will give them that guarantee then of course they won't use grease. Secondly, the manufacturer probably doesn't have much concern for whether a wheel can be easily removed again further down the line (more important that the wheel doesn't come off when it's NOT supposed to and cause an accident, than be difficult to remove when it's needed). Thirdly, adding a bit of grease to millions of wheel bolts is an additional cost.

 

So there's a conflict of interests between what the manufacturer prescribes based on safety, versus what a certain type of motorist expects (to be able to change a wheel at the side of the road with only a standard wheel brace to undo the bolts). To the manufacturer, the consequences of their wheel bolts working loose often would be significant. Whereas for me, whilst I recognise it as a risk, I've never had it happen yet, and having driven a car when I'd forgotten to tighten the wheel bolts up I'm confident I'd spot the early warning signs if it did happen, so my need to be able to remove the bolts easily outweighs the risk that they may loosen themselves.

[cfraser16 0 1 Cars]

This thread has turned out to be quite interesting.

 

This all kicked off on another forum I use, and I posted the question here because I respect the mechanical and engineering prowess of a number of our members. I'd never considered it before, as I always grease my wheel bolts and tighten by feel. I've used copper slip in the past but reverted to normal grease as I found the copper slip dried and was a bit more resistant to undoing (in hindsight, that property would be preferable and it's embarrassing that I didn't even think of that at the time). Without knowing, or even considering some of the engineering reasons for why wheel bolts should be treated in a certain way, I've been stuck in the mindset that I just want my bolts to go in smoothly with no risk of cross threading, and more importantly, I want the buggers to come undone again when I need to remove a wheel! Since I've never had a wheel bolt come loose before, I've never considered the risk of this happening due to using the wrong techniques!

 

So what I've heard (across both forums) is that:

1 - Using grease changes the torque being applied and could result in over-torquing

2 - Putting them in dry could lead to hitting peak torque before clamping force is reached

3 - Correct torque is required as it's the face of the bolt against the wheel that provides the clamping force. If the clamping force isn't reached, because the correct torque has not been applied, then the bolt could work loose

4 - Don't use grease between the mounting face of the hub and the back of the wheel. It's the friction between these surfaces that helps spread the rotational load of accelerating/braking. If the mounting face is greased then friction is reduced and more of the rotational force is transferred to the bolts. Only the spigot should be greased to prevent the wheel seizing on the hub.

 

So from the above, what I've taken away from this is to thoroughly clean both the bolts and the hub threads (obvious), use copper grease but only apply a bare minimum smear to the first 2-3 threads of the bolt (never get grease on the bolt face, and don't use so much that the grease squeezes back and out over the bolt face as you wind it in), and to do the bolts up to the correct torque. But that last bit is still a bone of contention as how do you know the correct torque if the grease is affecting that? Since I've never had a bolt work loose, I shall probably use a torque wrench as a guide but ultimately rely on feel, as I've always done.

 

With regards to above I would just point out that adding grease wont affect the applied torque but instead will affect how the torque is transferred into friction or tension and therefore stress in the bolt itself. Using grease will reduce the amount of torque lost as friction by reducing the coefficient of friction both between the threads and under the bolt head, therefore for the same applied torque a higher tension will be applied to the bolt. Therefore the risk with using a lubricant or grease on the threads is that the stress (tension) on the bolt is higher than intended/designed for if the bolts are meant to be torqued without grease, this could result in damage to either the bolt or the threads.

 

I realise that doesn't directly answer the question but it may help understand what the physical difference is if grease is applied or not!

[erbs 42 1 Cars]

i have used graphite grease for for over 20 years and not once have i had a stud snap because of it.

[B1ack_Mi16 67]

Always use copper grease myself on the wheel bolts too, much less hassle when undoing after a long and salty winter season.

Never use a torque wrench, tightens the bolts by the feeling.

In any case with or without grease you will feel when the bolt has "bottomed out" and really starts to give resistance.

 

After this point one can "angle tighten" a bit.

 

Can't say I've got any problems with corroded mating faces on any alloy wheels either.

[RichF 1 2 Cars]

Personally - clean up the thread, apply a little copper slip then jump up and down on a 4ft bar to tighten.

 

(ok, the last bit is a fib)

[grandos 16]

4 - Don't use grease between the mounting face of the hub and the back of the wheel. It's the friction between these surfaces that helps spread the rotational load of accelerating/braking. If the mounting face is greased then friction is reduced and more of the rotational force is transferred to the bolts. Only the spigot should be greased to prevent the wheel seizing on the hub.

 

With regards to your last point, I have also heard (at work) that putting a grease (substance) between the disc top hat face and your wheel will dramatically change the heat transfer properties of the two components and at best would just increase the likely hood of warped discs.

[lagonda 42]

That's all very well in an ideal world, but without grease, the wheel/brake disc interface corrodes to quite a degree, which would certainly give far more heat insulation than grease would. In theory, there could be some microscopic creep under braking...but really? With four bolts done up tight, the reality is nothing is moving...hands up how many people have found said interface polished by this movement? Regarding torque; the manufacturers supply a wheelbrace of a certain length because, using reasonable force on that should result in the nuts being tightened to around the correct torque.

For the record, I've always used a small amount of Copperslip on the bolt threads, and a very light smear on the wheel/disc interface. Never any problems, excepting wheel changing garage monkeys...always make a point of checking the bolt tightness once I've had new tyres fitted...almost invariably need a length of pipe over the wheelbrace to loosen them off.