Lug nut torque

[Scott'n'Wendy]

Some trailer sites will recommend torquing in two steps, some will recommend three. I go with two steps. How far apart in ftlbs should steps be? Like if I torque to 90 ftlbs, then step up to 100ftlbs, the wrench often will 'click' anyway before the nut moves. Stiction is the word I've heard. So if I want to hit a consistent torque, how much less should the first go around be before torquing to final?
This afternoon I was putting the winter tires on my Mom's car. I torqued to 70ftlbs first, then 95. The wrench went up to an eighth of a turn before hitting 95. Are my numbers far enough apart for an accurate final?

[Jlawles2]

I try to use 50-60% of the final value when going in 2 steps. The idea is to seat the rim and get it flat before cranking down on it so one side does not pop up or if it's not center correctly you find out.

If you run the first one to 100%, when you go back to check it, most of the time it is loose. I typically get movement when I do 50-60% on the second step to 100%.

[ThePowells]

Hopefully the resident rocket scientists will chime in. I'm sure that their respective organizations have spent years and hundreds of thousands in research. The best I can do is being taught 3 steps being 50%, 75%, 100% when building engines for race cars.

[Jlawles2]

I agree, the 50% is just to get things seated, then the following are for ensuring that distortion stays the same. People do not realize that the friction between the nuts and the rim along with the friction from the threads are what holds the lug nut in place. The side effect of all of this is elongation of the stud below the nut, and distortion of the rim by the wedge shape of the nut.

[Cate&Rob]

It is important to have clean dry metal surfaces on, the lug nut, the hub stud and the wheel. If there is any corrosion or rust on the lug nut, I remove this with a bench mounted wire wheel. For the lug nut sockets in the wheel, I use a fibre brush like the attached picture. For the hub studs, I use a similar fibre brush. If there is any corrosion on the hub and wheel mating surfaces, this should be removed as well.

I use a four step process for mounting a wheel:
1) Install the lug nuts with just a deep socket in your hand (this makes sure that threads are clean and nothing is cross threaded)
2) Touch the tire to the ground and torque the nuts to maybe 30 lb-ft. (This makes sure that everything is centred)
3) Lower the jack completely and torque the nuts to their final setting.
4) Check torque 50 miles later.

Rob

[Guest]

It is important to have clean dry metal surfaces on, the lug nut, the hub stud and the wheel. If there is any corrosion or rust on the lug nut, I remove this with a bench mounted wire wheel. For the lug nut sockets in the wheel, I use a fibre brush like the attached picture. For the hub studs, I use a similar fibre brush. If there is any corrosion on the hub and wheel mating surfaces, this should be removed as well.

I use a four step process for mounting a wheel:
1) Install the lug nuts with just a deep socket in your hand (this makes sure that threads are clean and nothing is cross threaded)
2) Touch the tire to the ground and torque the nuts to maybe 30 lb-ft. (This makes sure that everything is centred)
3) Lower the jack completely and torque the nuts to their final setting.
4) Check torque 50 miles later.

Rob

X2. But folks will want to stand off to the side with that bench mounted wire wheel. When I was a diesel tech long ago, a co-worker had a nut pulled in and thrown back out toward him and landed below the belt. I picked him up off the floor and walked him to get medical attention. Memorable from seeing how much pain he was in.

Jim

[Scott'n'Wendy]

2) Touch the tire to the ground and torque the nuts to maybe 30 lb-ft. (This makes sure that everything is centred)

...this is one of the numbers I was wondering about. How much torque before putting the weight of the vehicle/trailer on the wheels.
30 ftlbs is sufficient eh?

[TedS]

It should be enough. 30 lb-ft on a 1/2 inch fastener creates around 3600 lbs of force per lug.