Lug nut torque

[ShadowsPapa]

Personally I have always used a torque wrench on lug nuts unless it was beside the road in which case I took care of it asap. I worked on Caterpillar equipment for years at a dealership and torque was critical on a majority of fasteners. Some of that stuff was 3500ft lb+

I personally don't like using anti seize compound on lugs but I use lots of it elsewhere. Years ago I saw a set of tractor trailer wheels (stud piloted) with cone seats that were antisiezed and properly torqued come loose but on the same axle opposite side was torqued without antisieze and they were fine.

I could only assume that the cone seats need to be dry to aid in holding. We thought at first the studs had stretched due to over torque with the compound on the threads and seat but the micrometer said no.

HA - and I thought 250 ft/lbs for an axle nut was big. Whoa. My best friend in high school - his godfather was a diesel mechanic for the Milwaukee line. He worked at the roundhouse west of town. He gave us a tour one day and when I saw the nuts and bolts in those engines............ whoa.

Yeah, that taper not only centers things unless hub-centric but it's the taper that actually helps hold things in place as opposed to flat nuts against flat steel. The engine torque coming at the nuts sideways they just wouldn't hold without it.

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[whiteglad]

I use high pressure chassis grease on the wheel lug tapers and threads, and torque the lug nuts to 80-90 ft lb. Any lube reduces friction on the threads and/or taper, so torque should be reduced. Wear on the factory thread coatings will increase friction, as will rust and corrosion. If you do a search for torque specs, include the ARP fasteners site. They market a super slippery lube for their bolts and you will see that less torque is used with it compared to regular grease, oil, or dry. Never-seez and similar anti-seize lubes are mostly for high heat situations, but can be used elsewhere, of course. They aren't the best choice for low heat situations like lug nuts. Anti-seize is good for exhaust manifold bolts, etc.

 

[ShadowsPapa]

Super critical situations like racing engine rod bolts it's measured in bolt stretch, not torque, due to the things you describe.
There are different specs for the finish on the metal, too - is it zinc, phosphate, etc? Some platings change the friction.
I just clean things up well - make sure I remove any grit, dirt, rust, etc.
I have some charts somewhere that address that - comparing bare to plated and so on, as well as comparing lubed to dry torque specs.
Your 90 sounds about right for a clean and lightly lubed situation, depending on the vehicle, lug size and so on. Sounds about right for my cars.

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