Wheel nut thread

[Jackblack]

Howdy anyone verify wheel nut thread is 14mm ?

Tyre guys cross threaded my bolt .
Im gonna run a set of taps down it.

[Rob69]

Be carefull to ensure you have still have a good solid thread and the bolt is not just clinging on by a thread! Failing that a new hub. A new bolt as well. 14 x1.5

[zollaf]

if its cross threaded then its weakened. best to fit a new hub as rob advises. having a wheel fall off is not fun.

[Akash]

if its cross threaded then its weakened. best to fit a new hub as rob advises. having a wheel fall off is not fun. Is this an Audi thing or most cars that suffer? We bought two cars from Audi last year (A3/A6) and while the A6 bolts did remove ... eventually, the A3 didnt and in the latter case, it was an emergency wheel change after a puncture. Thankfully it happened right outside a car garage/mechanic however even they could not remove them. In the end, it went to Audi which was just down the road to get it sorted. Seems like they maybe overtighten the bolts?

The A6 was practically brand new but did have a wheel swap over done at the dealership but again, when it came to removing them, it was near impossible

[zollaf]

if any bolt is over tightened then damage will be done. thats any bolt, anywhere. the over use of windy guns and under use of torque wrenches, or even just a bar to final tighten, and also the method of putting bolt into the socket on the gun and offering it into the hole and then just winding it in, rather than starting it by hand, and its this that will cross thread it. so its not a cars fault, just the idiot thats too lazy to do his job properly.

[ukgroucho]

Is this an Audi thing or most cars that suffer? We bought two cars from Audi last year (A3/A6) and while the A6 bolts did remove ... eventually, the A3 didnt and in the latter case, it was an emergency wheel change after a puncture. Thankfully it happened right outside a car garage/mechanic however even they could not remove them. In the end, it went to Audi which was just down the road to get it sorted. Seems like they maybe overtighten the bolts?

The A6 was practically brand new but did have a wheel swap over done at the dealership but again, when it came to removing them, it was near impossible

I don't think this is particular to audi but a couple of experiences I've had when swapping my summer <-> winter wheels.

First time I did it the nuts came out fine but could I get the wheels off the hubs.... really tough. Google searches and I ended up under the car with a club hammer hitting the inside of the tyre. That worked but it's not a happy feeling. Apparently the trick if this happens at the side of the road with a puncture is to use the spare wheel as your "hammer".
The ACTUAL fix is that when the wheels are off you apply a little grease to the hubs before refitting. Audi apparently do not do this at the factory - I do it religiously at every wheel change now and have not had any other issues.

Last time I switched to winter wheels (a couple of months back) the front nuts came out fine, the rears were impossibly tight - and "Yes" I tighten them to the correct nM with a torque wrench, they'd simply tightened up or corroded in place. I managed to crack some of the regular nuts but ended up stripping the security socket (GRR). Off to the local audi dealership and with a new security socket and bolt (£40) and some help from a mechanic with a 4ft breaker bar we managed to crack them all lose.
Talking to the mechanic the trick (once again) is to apply a dab of grease to the nuts before you fit them...

[Rob69]

Some recurring problems here! Disimilar metals corroding, the alloy wheel being least noble compared to the steel hub and seizing to the hub, there are those who say copper antiseize should not be used on the alloy wheel due to copper being more cathodic than the alloy and the steel, resulting in the alloy being the sacrificial anode, use an aluminium antiseize instead?
Wheel bolts having been laid on the gritty floor of the fastfit tyre centre then being rattled in and up with a gun then a cursory click with a battered torque wrench, even though the bolts are already overtorqued. What if you apply grease to the bolt threads and they are then overtorqued; this stretches the bolt and threads even further than a dry bolt to the same torque, making it harder to remove the bolts once the grease has dried up from the brake disc heat.
It's a jungle out there!

[ukgroucho]

I use a "basic" Castrol LM bearing grease that I've had a tub of for 20+ years. Seems to do the trick nicely.

[bbrown1664]

If you use grease, DO NOT use the original torque values when tightening up.
Torque values are based on dry threads. Using grease means you will stretch/snap/strip the bolt before the torque is reached.

[Jackblack]

Snapping by hand not possible unless you stand on top of the bar and socket and bounce up and down on it with two fat men. ICE - Hydraulic Torque Wrench, torque multiplier (http://www.hytorc.co.uk/ice) and i have snapped M32 bolts with these and on purpose @ approx 7000 nm :-).
If you use grease, DO NOT use the original torque values when tightening up.
Torque values are based on dry threads. Using grease means you will stretch/snap/strip the bolt before the torque is reached.

[robes401]

If you use grease, DO NOT use the original torque values when tightening up.
Torque values are based on dry threads. Using grease means you will stretch/snap/strip the bolt before the torque is reached.

Just to be clear, a small amount of grease is applied to the centre of the hub or inner shoulder of the centre cap of wheel where it sits on the hub, not to the threads.

[bbrown1664]

Anything that enables the bolt to "slip" easier than the metal to metal contact it normally has will result in you winding more thread into the hole due to reduced friction. Admittedly it may not be much more than 1/8th of a turn but it all counts when you are looking at torque values and can result in weakening the bolts to the point where (eventually) they snap. I don't mean they will snap as you tighten them, but at some point later when they have a load applied (like in a corner) it can happen.

To be clear, I am not saying don't use grease, I am saying reduce the torque marginally if you do. I have used grease where required to prevent corrosion between dissimilar metals but reduce the torque by 5-10% unless the manufacturer quotes the torque and advises the use of grease.

[robes401]

Anything that enables the bolt to "slip" easier than the metal to metal contact it normally has will result in you winding more thread into the hole due to reduced friction. Admittedly it may not be much more than 1/8th of a turn but it all counts when you are looking at torque values and can result in weakening the bolts to the point where (eventually) they snap. I don't mean they will snap as you tighten them, but at some point later when they have a load applied (like in a corner) it can happen.

I think you're missing the point - the grease is not applied to the bolts or threads, nor should any grease enter the bolt holes. Just a bit of grease where the orange circle is on the image. 32397

[bbrown1664]

:thumpup

No problem. You are appluing it to the hub which stops the wheel sticking to teh hub, nothing to do with the bolts which also corrode to teh hub which is what I was refering to.

[Nigelo]

If you use grease, DO NOT use the original torque values when tightening up.
Torque values are based on dry threads. Using grease means you will stretch/snap/strip the bolt before the torque is reached.

Not quite correct - the Factory Workshop manual DOES specify using Optimol G-052-109-A2 paste (Castrol product) on wheel bolt threads after proper cleaning of course and using standard torque settings for your vehicle (120NM on my RS6 C7). Therefore always use the recommended anti-sieze paste with standard torque settings, no more no less.

hope this helps