[Bachu1]

Hi,

I have bought some spacers,

Would it best to put some copper grease on the back of the spacers so they don't get stuck onto the hub??

Any other advice wold be welcome..

Many Thanks

[crAbb]

Originally Posted by Bachu1

Hi,

I have bought some spacers,

Would it best to put some copper grease on the back of the spacers so they don't get stuck onto the hub??

Any other advice wold be welcome..

Many Thanks

No. The face of the spacer is where the torque is transferred.

[danb1979]

As above no - keep them clean/all mating surfaces clean

This ensures they're flush and you don't end up with wheel wobble etc...

By all means put something like ceramic paste on the hub lip, to help things not to stick as much

But absolutely nothing on the mating faces

[Bachu1]

ok.. so none on the back of the spacer which mates onto the hub???

The only reason i ask as many have said just whack some on it wont stick...

[TurboWeasel]

Nothing on any of the flat mating faces. A small slither of grease around the wheel bore holes is fine. That is what seizes the wheel to the hub, not the flat mating faces.

[danb1979]

Originally Posted by Bachu1

ok.. so none on the back of the spacer which mates onto the hub???

The only reason i ask as many have said just whack some on it wont stick...

As stated numerous times: "absolutely nothing on the mating faces"

So you'll need to clean it all off thoroughly

[Bachu1]

Thanks guys

Much appreciated :-)

[Allworth]

Originally Posted by crAbb

No. The face of the spacer is where the torque is transferred.

This is interesting. Always thought bolts play crucial role in torque transfer.
And yes, no grease on mating face it needs to be super mated and parallel, concentric ridge is only where you can apply a bit of grease.

[crAbb]

Originally Posted by Allworth

This is interesting. Always thought bolts play crucial role in torque transfer.
And yes, no grease on mating face it needs to be super mated and parallel, concentric ridge is only where you can apply a bit of grease.

The bolts merely hold the two surfaces together that transfer the torque.

[Allworth]

Originally Posted by crAbb

The bolts merely hold the two surfaces together that transfer the torque.

My rough calculation estimate that clamping force of 5 bolts are much less than the one of a brake caliper used to stop the torque transfer from a wheel. Now if we add roughness of a brake pads this will multiply this factor.
As I understand mating surface primary purpose is to give a wheel proper plane orientation.

[TurboWeasel]

It's 50/50. If the wheel bolts come loose, they don't all snap in half suddenly because the clamping force has disappeared. To say the bolts merely hold the surfaces together is too simplistic.

If you consider the huge shaft torque from the transmission's lowest gears being transmitted through a 82mm CV flange to a 18"+ wheel. That is nowhere near enough 'clamping force' to not slip. It's the bolts that do the majority of the work.

[Alscoob]

To throw a spanner in the works...

While I have always subscribed to the current thinking of dry mating faces, having removed the wheels from my G31 540 the other week I noticed that there was a extremely light film of lubricant on the hub mating faces to wheel, you couldn't really see it but could feel it. Was a bit like the old treatment on brake discs when they came wrapped in paper to stop them rusting but less of it.

The car was originally a BMW car and I'm the second owner, given the mileage when I got it at 10K and the service history, I would say that the wheels are unlikey to have been removed until I took them off. So having never had a brand new car myself, is this how they all come? If it is kind of throws the thinking out of the window?

[TurboWeasel]

Maybe some kind of modern PTFE type dry lubricant? They stopped using that cosmoline stuff years ago, in favour of zinc primer. Probably due to skin health reasons.

Another train of thought is HGV and tractor wheel hubs. Very small actual hub mating surfaces, but lots of large diameter wheel bolts.

[danb1979]

Originally Posted by Alscoob

To throw a spanner in the works...

While I have always subscribed to the current thinking of dry mating faces, having removed the wheels from my G31 540 the other week I noticed that there was a extremely light film of lubricant on the hub mating faces to wheel, you couldn't really see it but could feel it. Was a bit like the old treatment on brake discs when they came wrapped in paper to stop them rusting but less of it.

The car was originally a BMW car and I'm the second owner, given the mileage when I got it at 10K and the service history, I would say that the wheels are unlikey to have been removed until I took them off. So having never had a brand new car myself, is this how they all come? If it is kind of throws the thinking out of the window?

Could it be something like this?

I know a few folk that use something similar that is liquid but doesn't go on thick like ceramic paste/copper grease etc

https://www.amazon.co.uk/dp/B00295EF...v_ov_lig_dp_it

[TurboWeasel]

It's probably just post machining lubricant to protect the hubs whilst awaiting fitment to a car at the factory. If you buy a new bearing hub from BMW, it comes sealed in a bag with similar fluid on it.

[danb1979]

Originally Posted by TurboWeasel

It's probably just post machining lubricant to protect the hubs whilst awaiting fitment to a car at the factory. If you buy a new bearing hub from BMW, it comes sealed in a bag with similar fluid on it.

Yup; same with the F.A.G. bearings for E39s etc - but generally that gets cleaned off unless BMW now leave it on

[Allworth]

It can be preservative oil or an oily residue from some sort of coolant used when processing metal. Although regular brake discs are being cooked to a shape, there may still be some cutting where the oily coolant is used. Having it oily from a factory suggests that there is no direct harm in having an oily film coat, nor does it mean that it is any good, as oil can burn, attract dirt, and get into unwanted areas. But still a big no to a copper grease for this application, as it contains copper particles that may create an uneven surface.

[Kal101]

I’ll come clean on this one. I used ceramic grease on my hubs to prevent seizing after ( the garage) struggled to remove them in order to adjust the handbrake. I did ask the question then and was told on the forum this was a no no.

However after several years I’ve not noticed an issue.

[TurboWeasel]

9 times in 10 you don't get an issue. Some people are just very petty/anal about it and always have to bring it up.

I've lubed up my wheels and bolts for over 30 years and never had an issue. I don't fancy salt welded wheels thanks.

[danb1979]

Originally Posted by TurboWeasel

9 times in 10 you don't get an issue. Some people are just very petty/anal about it and always have to bring it up.

I've lubed up my wheels and bolts for over 30 years and never had an issue. I don't fancy salt welded wheels thanks.

Never had any issues with bolts; but have had issues with spacers and copper grease - so just don't touch it now

Ceramic paste on the hub etc - but not the mating faces

Been there/done that/chased the wobble

[Allworth]

Originally Posted by Kal101

I’ll come clean on this one. I used ceramic grease on my hubs to prevent seizing after ( the garage) struggled to remove them in order to adjust the handbrake. I did ask the question then and was told on the forum this was a no no.

However after several years I’ve not noticed an issue.

No, that's not accurate. If I place two pennies between the wheel disc and the hub and then tighten all the bolts, the wheel will be at an angle. However, if I use just one penny, the wheel will be at a lesser angle. Even if I apply your high-tech ceramic grease, the wheel will still be at an angle, albeit one that might not be noticeable to you. It's there. Remember, the absence of evidence doesn't disprove anything.
As said before there is a method to make wheel non sticky without touching mating faces.

[Kal101]

Originally Posted by Allworth

No, that's not accurate. If I place two pennies between the wheel disc and the hub and then tighten all the bolts, the wheel will be at an angle. However, if I use just one penny, the wheel will be at a lesser angle. Even if I apply your high-tech ceramic grease, the wheel will still be at an angle, albeit one that might not be noticeable to you. It's there. Remember, the absence of evidence doesn't disprove anything.
As said before there is a method to make wheel non sticky without touching mating faces.

Do you think that the tolerances on the mating surfaces, allowing for corrosion, grime, manufacturing allowances etc are that fine ?