Wheels stuck on

[Daffy]

Be careful when getting the wheels off with a hammer, I would suggest not hitting the rim but use a lump hammer on the tyre whilst slowly spinning the wheel - leave a couple of wheel bolts on their last threads to prevent the wheel falling on its face and damaging itself on the floor.

Don't ever put any form of grease on the vertical section of the wheel hub (the part with the holes for the wheel bolts) or the corresponding part of the wheel.

I would (& do) grease the spigot of the wheel (the hole in the middle of the wheel) as this is where the main of the corrosion is and will make removal of the wheel later much easier.

 

[Sabre]

If it sticks, force it. If it breaks it needed replacing anyway!

That's one doozy of a dent.

 

[Shaun Witts]

Don't ever put any form of grease on the vertical section of the wheel hub (the part with the holes for the wheel bolts) or the corresponding part of the wheel.

Why?
Because the grease may spread onto the brake disc?

 

[DXX]

Plus it’s designed to be metal to metal, using a torque wrench on a grease sandwich is pointless.

 

[Shaun Witts]

Plus it’s designed to be metal to metal, using a torque wrench on a grease sandwich is pointless.

I can see the logic behind that when its grease on the threads (but is there any supporting evidence anywhere?), but we are talking about the mating surface between wheel and hub - why not put a smear of grease here to minimise corrosion?

 

[mmi]

Braking and accelerating forces would bend the bolts back and forth, and eventually shear them. The bolts are designed only to clamp the wheels on the hub, not to bear bending forces.

 

[DXX]

I can see the logic behind that when its grease on the threads (but is there any supporting evidence anywhere?), but we are talking about the mating surface between wheel and hub - why not put a smear of grease here to minimise corrosion?

Engineering practice, doesn’t just apply to wheels.
Had to help somebody out with loose injectors on a Transit not long back, they had put the injector seals in with a blob of grease!
Ships propellors on tail shafts, etc…..

 

[Daffy]

Why?
Because the grease may spread onto the brake disc?

Because wheels stay put because the bolts achieve a minimum clamping force between the wheel and hub, a layer of grease albeit a few microns thick will spread reducing the clamping force and all of a sudden you have movement and that’s bad for reasons I don’t need to explain.

Also never put oil or grease on wheel bolts as modern oils and greases are designed to make things slippery so you risk over tightening the bolts (even with a torque wrench as the friction between the bolt and threads/wheel is reduced), they are also designed to last so won‘t dry out so continue to lubricate the bolt, again that’s bad.

WD40 or GT85 is good to lubricate the bolts as it doesn’t last very long and isn’t as slippy as oil/grease and they dry out fairly quickly and create a stiction between the bolt and hub/wheel where they contact.

just a spray of GT85 on the bolts and a smear of grease on the hole in the middle of the wheel (that’s the bit that contacts the sticky out bit of the hub) , do this and your wheels will be tight and they’ll only come off when you want them to.

 

[JOG]

Because wheels stay put because the bolts achieve a minimum clamping force between the wheel and hub, a layer of grease albeit a few microns thick will spread reducing the clamping force and all of a sudden you have movement and that’s bad for reasons I don’t need to explain.

Also never put oil or grease on wheel bolts as modern oils and greases are designed to make things slippery so you risk over tightening the bolts (even with a torque wrench as the friction between the bolt and threads/wheel is reduced), they are also designed to last so won‘t dry out so continue to lubricate the bolt, again that’s bad.

WD40 or GT85 is good to lubricate the bolts as it doesn’t last very long and isn’t as slippy as oil/grease and they dry out fairly quickly and create a stiction between the bolt and hub/wheel where they contact.

just a spray of GT85 on the bolts and a smear of grease on the hole in the middle of the wheel (that’s the bit that contacts the sticky out bit of the hub) , do this and your wheels will be tight and they’ll only come off when you want them to.

Good layman’s explanation of what not to do and what you can do! Thank you

 

[Shaun Witts]

Because wheels stay put because the bolts achieve a minimum clamping force between the wheel and hub, a layer of grease albeit a few microns thick will spread reducing the clamping force and all of a sudden you have movement and that’s bad for reasons I don’t need to explain.

Also never put oil or grease on wheel bolts as modern oils and greases are designed to make things slippery so you risk over tightening the bolts (even with a torque wrench as the friction between the bolt and threads/wheel is reduced), they are also designed to last so won‘t dry out so continue to lubricate the bolt, again that’s bad.

WD40 or GT85 is good to lubricate the bolts as it doesn’t last very long and isn’t as slippy as oil/grease and they dry out fairly quickly and create a stiction between the bolt and hub/wheel where they contact.

just a spray of GT85 on the bolts and a smear of grease on the hole in the middle of the wheel (that’s the bit that contacts the sticky out bit of the hub) , do this and your wheels will be tight and they’ll only come off when you want them to.

I’m going to play devils advocate here…

Are you really suggesting that the wheels might come loose (have movement) when any grease that is applied to the mating surfaces spreads and reduces the clamping force? Whilst it may well be possible to measure that effect, I struggle to believe that it can affect the safety of the wheel retention.

I have considered the same concerns that you raise regarding greasing bolt threads. I can see the logic behind that, but I have never seen an engineering report to substantiate it. Is the stiction of dry threads that much more then greased threads that bolts can be over tightened (stretched) beyond their design spec If greased? What about the reverse effect of old, dirty and rusty threads? So I assume that there is sufficient tolerance in the bolt design to cope with a bit of corrosion resisting grease. And I also grease the chamfer and bolt shaft within the chamfer section - which must also have an effect.

So, what do we all think? Has anyone got evidence to support either direction? I would like to know as I swap to winter wheels each year on two cars, and it is always easier when the wheels come off easily!

 

[JOG]

when the wheels come off easily!

I think that answered your question!

 

[mmi]

>>Pocket Guide to Tightening Technique<<

(PDF) Effect of Lubrication on Friction and Torque-Tension Relationship in Threaded Fasteners

PDF | In this research, three types of lubricants are investigated for their effects on the friction and torque-tension relationships in threaded... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

 

[Daffy]

I’m going to play devils advocate here…

Are you really suggesting that the wheels might come loose (have movement) when any grease that is applied to the mating surfaces spreads and reduces the clamping force? Whilst it may well be possible to measure that effect, I struggle to believe that it can affect the safety of the wheel retention.

I have considered the same concerns that you raise regarding greasing bolt threads. I can see the logic behind that, but I have never seen an engineering report to substantiate it. Is the stiction of dry threads that much more then greased threads that bolts can be over tightened (stretched) beyond their design spec If greased? What about the reverse effect of old, dirty and rusty threads? So I assume that there is sufficient tolerance in the bolt design to cope with a bit of corrosion resisting grease. And I also grease the chamfer and bolt shaft within the chamfer section - which must also have an effect.

So, what do we all think? Has anyone got evidence to support either direction? I would like to know as I swap to winter wheels each year on two cars, and it is always easier when the wheels come off easily!

I’ve only said what I believe to be the safest way to fit a wheel, if you want to grease the mating faces of the wheel/hub then crack on, although I‘m not sure how anyone could think that removing the friction and relying solely on the wheel bolts to take the shear forces applied by the drive is a good idea.

I wouldn’t fit a rusty wheel bolt, I’d clean it up or throw it away and I wouldn’t use grease on a wheel bolt - ever.

There are lots of studies on wheel loss on HGV’s which whilst bigger have the same basic design and fixing applications, I suggest you google these and make your own mind up.

 

[Daffy]

View attachment 141011

https://www.atlascopco.com/content/dam/atlas-copco/industrial-technique/general/documents/pocketguides/9833864801_L.pdf

(PDF) Effect of Lubrication on Friction and Torque-Tension Relationship in Threaded Fasteners

PDF | In this research, three types of lubricants are investigated for their effects on the friction and torque-tension relationships in threaded... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

Beat me to it

 

[DXX]

Is the stiction of dry threads that much more then greased threads that bolts can be over tightened (stretched) beyond their design spec If greased?

Yes, well known fact within the engineering world, time served fitter & turner, 44 years engineering experience.

 

[dubber36]

Way back when vehicles were actually 'serviced' the wheels would be taken off regularly, so this would never have been an issue.

 

[Paynewright]

I’ve never lubricated wheel bolts or nuts. On my 911 the wheel bolts have an ally collar on a steel bolt. The collar / bolt interface has to have alu-slip applied.

Re wheels sticking on - I clean up the hub with a wire brush in the cordless drill and the alloy with a scotchbrite pad then a smear of coppa or alu slip on the protruding part of the hub down to the radius with the wheel mounting face. Never had a problem getting a wheel off after doing this nor any fling out of anti-sieze.

 

[Shaun Witts]

Interesting responses - thank you.
More research on my part obviously required...

 

[YellowHound]

Interesting.
Porsche recommends the use of 'Optimoly' on their wheel bolts.

 

[Paynewright]

Interesting.
Porsche recommends the use of 'Optimoly' on their wheel bolts.

From what I’ve researched its only between the bolt head and collar not the threads. I’ve compared the porsche bolts with the VW Transporter bolts on the bench and they are near identical apart from the collar being ally on the porsche bolts.