S80: Wheels/Brakes Wheel bolt torque

[Peter2400]

Hi! What is the correct wheel bolt torque value for a p3 s80 (2008)? My printed owners manual says 140 Nm, online owners manuals says 85 Nm... First seems a bit too much, second seems too low. What torque value are you guys using? Thanks!

[barrybritcher]

def bolts? on p2 bolts its 140nm so that might be some help.

[barrybritcher]

https://www.puretyre.co.uk/torque-se...-16-245/45R17/

[Peter2400]

Okay, so its 140 Nm then. Thanks!

[apersson850]

Now, everybody has alloy wheels, but some older models, where steel rims were more common, specified 90 Nm. So that's probably where the 85 Nm comes from.

[Kev0607]

I got my tyres replaced not so long ago & they must have tightened the lug nuts with an air impact. When I come to replace my brakes, I had to stand on a 1/2 inch breaker bar to loosen them to get the tyres off... Absolutely crazy! However, the threads all appeared to be fine luckily. There was no need to tighten them the way they did though!

I tightened them to the recommended spec of 140nm since doing the brakes & had no issue removing the tyres.

[barrybritcher]

they are stiff by default - when removing mine I have to put a fair amount of weight on the breaker bar (when done to exactly 140nm)

[Kev0607]

My lug nuts were stiff alright. I should re-phrase my post above... I had to jump on the breaker bar to get them off & use a scaffolding tube for more leverage!

[green van man]

If the threads are dry tightening to correct torque will result in difficulty removing them.

Now in the expectation of a horrified reaction, I grease my wheel bolts and studs, have done for 50 years and never had a wheel fixing come loose untill I wanted to take the wheel off.

These days getting old I use a battery rattle gun to remove wheel fixings but removal by hand tools is very possible without excess effort on my cars.

Years ago in collage I was taught torque settings were for lightly lubricated threads. Oil will throw out under centrifugal force so use grease. I have done ever since and never had an issue with any wheel I fitted because I torque to recommended settings.

I know Mercedes say dry threads and have watched ATS struggle to remove wheels on my works sprinter and seen ripped threads and wheel nuts have to be replaced and they were torqused up when fitted.

Your cars you choise, I know what works for me.

Paul.

[apersson850]

It's when you tighten them dry they come lose. The lubrication is necessary to get the correct tension in the bolts, with the recommended torque.
If you tighten too much, you may stretch the bolts irrevocably. In such a case, the bolts should be replaced with new ones.
If you tighten with a pneumatic driver, use torque rods.