This brings up a good point, but everything I say is a good point, so no surprise there....anyway, the kids at tire shops, the biggest being Discount, are well trained. They are trained to use a torque wrench. And they are also given air impact wrenches. As I have said, these should be used for removal. So what do these kids do even after they become managers? You may ask? They use the impact to tighten the lug nuts. Then they use a torque wrench. Which clicks immediately. So what is the torque value of that nut? Nobody knows. They do look up the torque for that vehicle or it is printed on the order. So they set the wrench like they were trained....and as I said, it clicks right away after the air hammer hammered the nut on. Don't know what the max torque is on their heavy duty guns but could they be damaging the studs? ALL OF THEM ? if you buy 4 tires? Maybe, sometimes.
Second issue: They are trained to put the nut on by hand before using the impact. That's correct. So they make four twist of their hand/wrist. That's a lot of fastening. It's actually just one rev, one thread or less. If it's a little off, known as cross threaded, it gets ram hammered on and he never feels the resistance. Then he puts the torque wrench on it and it clicks right away.
Just food for thought for you insurance guys. Using a torque wrench is no guarantee at all. The nut has to be turned a rev or two by the torque wrench. Tires shops are using the wrong technique. You don't know where you are stopping an impact wrench, you just stop after it ratchet hammers a few times or a lot of times. They should be banned for tightening. Or use a low voltage DC cordless nut driver with an adjustment. The need to get customer thru put has negated training....or the Corporation doesn't realize they have a cart before the horse situation.
