Lug bolt tightening torque

[gugel]

I'm sure this question must have been asked before, but I couldn't find anything using Search.  With alloy wheels, how tight should the lug bolts be?

Chris Earnest

[waltklatt]

Tightening sequence should be in a star shaped pattern. Start with one and skip the next and so forth, till all are tight.
Not sure how tight they should be.  Keep in mind you need to loosen them again in the future if necessary.
Walter Klatt
1967 220SL-diesel
1963 230SL-gas

[mbzse]

quote:Originally posted by Chris E

With alloy wheels, how tight should the lug bolts be?

Chris and List,
Alloy wheels are torqued to 110 Nm (81 lbf ft),
Steel wheels to 90-100 Nm (66 to 74 lbf ft)

Like Walter mentioned, torque the bolts in a ”star” pattern using a hand torque wrench. Do not allow workshops to use an air powered impact wrench, even though they will claim it is "set" to the correct torque...![:0]

If you can't fight the workshop people off, re-torque yourself when you have arrived back at your garage.
Wrong torque can cause wheel disks or brake disks to become twisted and then wobble...


/Hans in Stockholm

[gugel]

Thanks for the info.  Of course I always tighten in a star pattern, but needed to know the torque spec.

quote:Originally posted by mbzse
If you can't fight the workshop people off, re-torque yourself when you have arrived back at your garage.
/Hans in Stockholm

This is a good point.  I haven't had any trouble with the 230SL, but recently a major, well-respected tire shop tightened the lug bolts on our ML320 so much that it ruined the threads on one bolt, so later it had to be snapped to get it off, necessitating an expensive repair to remove the rest.  Unfortunately I can't prove the shop did it (because the car had been at the dealer at about the same time), but there's no doubt in my mind.

Chris

[Chad]

Chris, exactly that problem happened years ago to a lug bolt on a 300CD used to drive (bundtcakes). It was a bit annoying. Not sure how tight they were torqued before as that was the first time I had taken wheels off after purchasing the car.

Great to have this advice/info from Hans!!