ninjacoco

I see in the factory service manual that the torque for lugnuts is something crazy like 96 ft-lbs, but then again, I'm pretty sure my car ('84 NA 944) came with the kooky aluminum lugnuts, too.

These have been replaced with nice, heavy steel nuts. Is the torque spec for my NUTS OF STEEL (hehe) the same as the aluminum ones?

Dougs951S

As a matter of habit, I always torque all lugs to somewhere in the 100 ft-lbs region regardless of make of car and material composition of the nuts. Unless of course they are center locks, those need ~350-400 ft lbs! At the shop I was in the habit of using my 3/8th impact to spin on lugs.

f1rocks

95 ft pounds is sufficient.

IF YOU PAINT THE WHEELS........don't paint the lugnut area. I torqued them before a 90 minute enduro once running "fresh" wheels. The paint in the lugnut area got soft with the extended heat and the lugnuts came loose at the 85 minute mark. I finished the race but it was shaky!

I wouldn't over torque as it will potentially cause stud failure (stub failure with steel nuts bad....)

Carry a spare rear hub, one day, one race you'll need it.

JimV8

Just typing out loud. The torque is really about exerting a clamping force between the hub and the wheel. I'd worry about torquing beyond spec as that could stress the wheel at the holes and induce cracking. IMHO it makes no difference if the lug is alloy or steel. FWIW I also have nuts of steel.

Van

But 96 ft/lbs is the spec.

Same torque spec for steel or aluminum.

Fara

I always thought the torque spec was one foot pounding on a tire iron?

Van

I didn't know there were hillbillies in Oz...

Fara

Sure there are, they are called bogans.

There was a bogan warning in place for the end of the Sydney to Hobart yacht race.

ninjacoco

Lulz, bogans.

...

I feel the need to do a burnout now.

wingnut

To further explain, the clamping force comes from elastically stretching the stud/bolt.

Also of note is the call-out for lubricating the threads and nut bearing surface (callot) with Optimoly TA or similar. The proper clamping force will not be achieved if it is not lubed due to higher running torque, resulting in an under-torqued static condition.

Tangentially FYI - the default condition for any torque spec is no lubrication if none is specified. AKA " clean and dry", meaning exactly that. Torque is not a real precise method of obtaining the desired clamp force; at the extreme there can be over 25% variability in the outcome for the same applied torque to the exact same item. So sticking close to the given specs - value and lube - are important to achieve a clamp force in the acceptable range.