Preventive greasing of wheel centres

[betaone68]

I suggest as soon as you receive your car that you disassemble the wheels and grease the wheel hub centring with copper grease (it resists high temperatures and does not drip).
On my car with 50 km they had already started to rust.

Here after cleaning and greasing.

 

[8YARWY]

Always been the same with Vag cars.

The best one was seeing cars that were bought from dealers used, having supposedly had the 115 point check, which means having the wheels off, yet the first time a new owner needs a wheel off they discover it almost impossible to remove it.

Takes minutes to remove a wheel / clean the mating surfaces up and apply a little grease around the hub lip, and makes for easy removal next time.

One thing I’ve noticed about my 8Y is this time the rear hubs haven’t started to rust…….yet. On the 8V even with a coating they started to rust pretty early.


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[Mike.46]

The OP (betaone68) has made a nice job of applying his copper slip, unlike the 'professionals' attempt pictured below.....................and even more of a 'no-no' when he's about to slap a wheel spacer into the 'slippery' mix as well

 

[8YARWY]

The OP (betaone68) has made a nice job of applying his copper slip, unlike the 'professionals' attempt pictured below.....................and even more of a 'no-no' when he's about to slap a wheel spacer into the 'slippery' mix as well

View attachment 262770

I’ve tested this theory in my 8V.

I applied copper slip to the hub face (lol granted not as much as in the above image) on one front wheel, torqued up the bolts and ran the car for a few weeks, I then checked the torque / bolts / removed them and took the wheel off, yes the alloy was easier to remove, but it didn’t exactly fall off the hub with no bolts in.


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[Mike.46]

I’ve tested this theory in my 8V.

I applied copper slip to the hub face (lol granted not as much as in the above image) on one front wheel, torqued up the bolts and ran the car for a few weeks, I then checked the torque / bolts / removed them and took the wheel off, yes the alloy was easier to remove, but it didn’t exactly fall off the hub with no bolts in.


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I imagine in the vast majority of cases it would be ok with the copper slip applied all over the mating faces, but there is a reason why manufacture's always state that the mounting faces must be free from oil and grease, maybe they look at not just driving around for a few weeks but the possibility of someone taking their car to the Nurburgring, or even a track day with the increased loads of heat, acceleration and stopping

 

[8YARWY]

I imagine in the vast majority of cases it would be ok with the copper slip applied all over the mating faces, but there is a reason why manufacture's always state that the mounting faces must be free from oil and grease, maybe they look at not just driving around for a few weeks but the possibility of someone taking their car to the Nurburgring, or even a track day with the increased loads of heat, acceleration and stopping

I can see why a lot of copper grease like in your above R44 picture would / could lead to wheel movement on the hub during extreme driving etc, my reason for testing it was to see if ‘normal’ driving would have an effect on bolt torque values.
Small % of cars get used on track though vs regular drivers.

The alloy mating face has several casted cut outs in it anyway, meaning even less alloy material touching the disc hub.

Would I run with grease on the hub face all the time ? No, but I just wanted to see if anything happened hence the experiment.


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[betaone68]

Copper grease should only be put on the wheel centring and not on the mating surface between hub and wheel. The five screws should primarily only work in tension and not in shear. When you tighten the screws you press the wheel surface onto the hub and it is the friction between these two surfaces that transmits the power.
Also the threads of the screws should never be greased. By greasing them you reduce the friction and risk tearing the threads . To explain myself better, let me try this example. Assume that at a torque of 14 kgm the screw makes a rotation of 90 degrees after it has reached beat. A screw with a greased thread will rotate 180 degrees after reaching the stop, putting much more stress on the threads.

 

[8YARWY]

Copper grease should only be put on the wheel centring and not on the mating surface between hub and wheel. The five screws should primarily only work in tension and not in shear. When you tighten the screws you press the wheel surface onto the hub and it is the friction between these two surfaces that transmits the power.
Also the threads of the screws should never be greased. By greasing them you reduce the friction and risk tearing the threads . To explain myself better, let me try this example. Assume that at a torque of 14 kgm the screw makes a rotation of 90 degrees after it has reached beat. A screw with a greased thread will rotate 180 degrees after reaching the stop, putting much more stress on the threads.

Agreed on the threads.

The mating surface grease argument is as old as car forums….. some won’t / don’t and then there are others that have done so for years with apparently no issues.

Most of this comes down to a personal preference.


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[AlS3BE]

Another reason for not greasing the mounting surface is if the grease get hot and runs out it will be all over the disc surface which is the last place you want any kind of grease.

 

[Mike.46]

Agreed on the threads.

The mating surface grease argument is as old as car forums….. some won’t / don’t and then there are others that have done so for years with apparently no issues.

Most of this comes down to a personal preference.


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Once the HP starts getting really serious (around 900/1000hp) like some Iroz cars and similar are doing the use of any spacer or grease on the mating surface is going to be even more of an issue, also the use of slick tyres (or the Santa Pod type track surface) will increase the force on the wheel to hub mating surface as well, my mates 850hp beetle actually twists the spline where the driveshaft enters the hub (and it's not std beetle either, probably a 35mm spline) scary things happen with grip

 

[flybynite]

Ah this old chestnut

I use Alumslip on anything that touches aluninium or aluminium alloys, made by the same people as Copaslip! I use red grease anywhere it could get on the rubber bits as they don't like either of the above.

That said FWIW I never had an issue back in the days we used copaslip on everything.