Does it make a difference if the wheels are loaded (on the ground) or not loaded on a lift when tightening wheel nuts?

 

In my opinion, I would think that there is enough compliance in the tire that you could probably torque the wheel if you've seated the lugs at least hand tight with the wheel off the ground.
However, just in case that isn't true, I always snug the lugs to about 15-20 ft./lbs (just a guesstimate) with the wrench, before I lower the car to the ground. Then I use the torque wrench and go through the proper sequence.

 

The ideal would probably be "unloaded", but tightening lug nuts while the tires are on or partially on the ground is OK. The important thing is to use a sequential, cross-hatch pattern to insure proper fit. This will help prevent what many folks report as "warped" rotors. :)

 

The quick and dirty answer is yes and no. I do it both ways. But if given a choice and time the best is to torque it to the required values while in the air (unloaded). The design and engineering of say the Z06 wheel is centered to the center point and the reason being to let the unloading conditons lets the wheel come as close to center as reasonalbly practical. To lessen the chance of warped rotors, put a gradual application of torque say 30, 60, 90, 100 ft #'s of torque using a opposite star pattern.

 

Good question - I've been meaning to ask it myself. I'm still weighing the answers I got to my "what torque wrench to buy" question. My Little Lift is on the way but i would like to get my chrome McGards on now. :D

 

in the air is always preferred, even if there is enough compliance (IMO there is not) it is very hard on the wheels lug seats; not all aluminum wheels have inserts and it will throw off the actual torque setting of the nut. Having an extra foot on the brake makes it possible or if you only lower the car enough to put the minimum load needed to keep the tire from turning if you're by yourself.

IMO, the need to retorque the nuts after a drive or two is much greater if you torque them with the wheels fully loaded on the ground. You should re-torque them anyways, improper lug nut torque is the #1 cause of warped rotors.

 

TeamZ06 is correct.
If possible have someone push on the brake pedal while you torque the wheels.
If no one is available I lower the car to where the tire is just touching the ground and I can torque the wheel without the tire turning.
Also, I have seen people put a wheel chock under the tire to keep it from spinning while the wheel is being torqued.
Point is do not load the wheel while torquing.
Dave

 

I disagree. The friction force that has to be overcome to get the nut moving is significantly greater than the friction force when it is moving. If you tighten the nut to close point below the final torque value, say 60 ft lbs when you are trying to reach 75 ft lbs, you take the chance of not overcoming the static friction force needed to get the nut moving before the torque wrench clicks, which will result in the nut being undertorqued.

The preferred method is to torque all the nuts in the diagonal pattern just to the point you feel them tightening down. At this point the wheel is seated on the hub. You can use a low torque wrench value, say 15 ft lbs, but it is not really necessary once you learn the feel of it. Then with the torque wrench, tighten each nut in the diagonal pattern with a single, continuous sweep until the proper torque is reached. If you do this properly with the wheel unloaded you stand a much better chance of getting them torqued properly.

For the same reason, the preferred method for retorquing a lug nut is to first back it off slightly, then torque it in a single continuous sweep to the proper torque value, continuing with the same process in a diagonal pattern with each of the other lug nuts.

You should always retorque the lug nuts as stated above following one good heat cycle (heat up & expand, cool and contract).

 

If I read your post correctly, what you are saying is to get the wheel marginally seated, (app 15 #'s each) then go for full torque, ie 100#'s. The whole issue of lessening the chance of warped rotors is to have more appled torque evenly spread before the final torque value application of 100 #'s.

 

Here is my technique:
1st pass 25ft/lbs
2nd pass 50ft/lbs
3rd pass 100ft/lbs
Phillip