I just swapped to new tires for the cold season. The tire shop used Docutorq, and I watched as they were tightening. At first, they set 86 ft/lb even though I printed out a paper with the lug key for 108 ft/lb, and when they were "finished" I had them go back and set Docutorq for 108 ft/lb. Their system, I think, automatically bumped it a few more to 111 ft/lb.

Anyway, once I need to re-torq down the road, my question is: Is it necessary to raise the vehicle, lifting the wheels off the ground in order to loosen and re-tighten them? Or can I just use a breaker bar and torq wrench while the car is sitting on all 4 wheels? Would that bend the wheels if I loosen them while the car's weight is still on them?

 

First off don't worry about a few extra foot pounds. Second, its always best to check the specs on the ground because you don't have the leverage in the air. Third, it won't hurt anything to loosen the nuts on the ground. Keep in mind that the lugs simply keep the wheel tight against the hub. The hub itself is what supports the weight of the vehicle. So long as you torque or untorque in the proper pattern (star pattern for 5 lug) you won't bend anything.

 

I always lift the car to torque lug nuts. Snug the nuts with the wheel in the air, then lower it so there's enough friction to keep the wheel from turning. IMHO lug nuts should be tightened with most of the weight off the wheel.

Lone Wolf speaks wisely about a few foot-pounds not mattering, and the importance of a star pattern. It's also a good idea to tighten in two steps, 2/3 of the way first, then re-star the rest of the way.

Just got back from getting my Honda inspected, and a chore for this afternoon is to loosen and re-torque the wheels they pulled to inspect the brakes. The guy just used an air wrench, tightening in a circle. Foo! At least he knew how to pull the rear drum off, and didn't attack it with a crowbar like one inspector did.

Ken

 

Maybe going in two steps is just a habit from torquing cylinder heads, but it doesn't hurt.

Just for anality sake, I actually go in three steps: snug (so I know the wheel is sitting properly), then half then full. IMHO, whenever there is more than one nut/stud/bolt holding a part in place, all should be snugged in place before tightening any.

On tightening lug nuts - until my Accord got to be 10 years old or so, I never had a problem from guys in gas stations air-wrenching wheels on going in a circle. But at some point I started getting a vibrating brake pedal shortly after inspections. Re-torquing the lug nuts in the proper order would fix that.

Ken

 

The most important thing is to re-check torque 100 miles later.