Thread: 140NM Wheel Nut Tightening Torque

[QUOTE]I wouldn't overthink it /QUOTE]

Probably the best summary of this issue in the thread!

Originally Posted by DiscoJeffster

As I said, there’s enough margin of error in these things that it’s rarely an actual issue.

True for safety, but I've certainly worked on more than one type of vehicle where unevenly or grossly over torqued lug nuts will lead to rotor warping after a few good heat cycles.

I have several 1/2" torque wrenches around the place. They may not be incredibly accurate, but they are "close enough" and more repeatable than my elbow clicking.

Originally Posted by BradC

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Now we've looked at the thread, what about the wheel? Different materials, and alloys all have differing coefficients of friction. So in theory doing up the same nut on the same thread retaining a steel wheel will be different to an alloy wheel. ...............

IME (RRC) all nuts going on studs for steel wheels have a tapered seat and nuts going on studs for aftermarket alloy wheels have a flat seat. I would not expect the 'correct' torque values to be the same for each type of wheel.

Wheel studs for RRC's have a different symbol marked on the outer end of them for alloy wheels compared with those for the early steel wheels. Pretty sure there is a difference in length.

DL

Yes the early steels wheels have a shorter thread which is designed to be flush with the top of the nut when tightened.
But as long as there is about 80% engagement it is OK.
Regards PhilipA

Originally Posted by 101RRS

Who lugs around a torque wrench to tighten up wheel nuts - a standard wheel brace tightened by arm until you cannot move it anymore is spot on. Never had an issue.

Actually…I do - I have a 1/2” TW in my car tool kit. I had a trailer tyre come off on our new camper trailer in its maiden voyage because the guy forgot to check the wheel nuts as part of his pre delivery check. As a result I’ve been quite religious in checking the trailer and car wheel nuts before going on a long trip ever since.

Incidentally I had no idea that 140nm was the torque value. I thought it was 120nm. Thanks everyone, I’ll wind the TW up a bit. I normally do the trailer to the same as the car.

Originally Posted by 101RRS

Who lugs around a torque wrench to tighten up wheel nuts - a standard wheel brace tightened by arm until you cannot move it anymore is spot on. Never had an issue.

I certainly do! Takes up very little extra space in the wheel well.

Originally Posted by BradC

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Now we've looked at the thread, what about the wheel? Different materials, and alloys all have differing coefficients of friction. So in theory doing up the same nut on the same thread retaining a steel wheel will be different to an alloy wheel. Is that in the manual? What about a dry thread and lubricant on the wheel/nut interface? Corrosion on the wheel? Aluminium oxide has a different coefficient of friction to clean aluminium. Is the wheel anodized?

It's more than just "dry good, lubricated bad, ugh".

Don't forget the coefficient of expansion of your aluminium wheel vs the steel of the stud - that will also increase the tension on the stud and is probably why at 140NM wheels studs are very under stressed.

One of my fave youtubers has to be Project Farm.

His anti seize video here :

Shows that anti seize can, but doesn't necessarily reduce the torque required for loosening nuts.

But following on from the data he got from the 'control' nuts ... and my experience with the easy to snap Inter wheels studs and the steel wheels on my RRC and bent up wheel brace, and the subsequent need to improvise with hacked tools to remove a flat in the middle of nowhere ...
A little bit less torque on removal is better than having it stuck hard when you least want it too.

So if an average of say 10-15% lower torque is needed to remove(with anti seize), there shouldn't be too much issue to add say 10% more to the required value to begin with if you use anti seize. Or just use cheaper no name anti seize
As already mentioned wheel nuts are under stressed compared to their ultimate torque rating.