I have heard that if you use an air gun you can overtighten lug nuts and damage rotors.....my question is, Do some, most, places set the pressure on theirs so this won't happen. If I ask them to hand tighten lug nuts, and they say that they set pressure on guns so this won't happen, I'm just wondering if that is true or they are just lazy..??

 

nope they are lazy.... industrial air guns even on the lowest setting tighten to about 200 foot/pounds.... way more than most anything should ever get.....

i know america's tire company uses pre-torque sticks then actually torque them down after... the torque sticks are pretty good, a lot better than the unmolested power of the gun..... but they to overtorque, its just the nature of using air tools to tighten stuff.... and yes, it can warp the rotors

 

Usually, they use a torque stick that is rated lower than your recommended spec, and then torque to spec with a torque wrench. If they don't use a stick, there can be problems.

However, if they DO overtighten and you can document it, they have to pay for damages, just like if they undertighten and a wheel falls off (have seen both, usually with overtightening the bolt shears).

 

depending on where you go, they might use a pretorque stick, i can tell you that even these for the correct rating on your vehicle thye still overtighten, by around 20 ft/lbs but it is a lot better than having them cranked on with the gun on the regular setting.....

the old company i worked for, if you told them to hand tighten it, they would, because you asked...... and if there was a problem, you would call the corporate office, complain, and htye would take care of the issue, normally resulting in a check being mailed to you....

 

A little OT: How do those "pre-torque" sticks work any way? They don't look like anything but a socket extension, what am I missing?

 

they are weaker than regular metal, and are brittle they snap into pieces if there is too much torque applied to them.... they do overtorque the wheels though, i know they arent supposed to, but they still do it......

 

Thanks for all the help.....It's "hand tighten my lugs, and I'll watch...or I'll take my business elsewhere (and complain to corporate)

 

A pissed off mechanic can exert more than 300lb/ft with a regular 2 foot breaker bar, using hands.

 

at that point you tell them corporate will be hearing about it, and any damages will be coming out of that store..... no matter how pissed a mechanic gets at the customer, ultimately its the customer's money and vehicle, even talking to the manager @ that point will get things cleared up quick!....

 

I never let anyone near any of the wheels ont he 3G or Taco with an impact wrench. Mainly becuase of the overtightening. I usually set hte torque spec myself (72ft. lb.).

Also, the wheels ont he 3G are painted (AR ATX Victor), and an impact wrench can hcip the paint.

 

after Discount Tire stripped a bunch of the wheel studs by using a torque wrench, I've started insisting that places do the tightening by hand. Most are decent about going ahead and doing that ...

 

sounds wierd that they stripped it using a troque wrench tightening it, unless they were grossly previously damaged or crossthreaded....

 

they were neither.

 

I think Rocky is using the term "torque wrench" in the place of "impact or air wrench".
A torque wrench is a hand tool which clicks or otherwise indicates when you have reached a certain torque value, whereas a impact wrech is an air powered tool which can provide extremely high torque, with no real control over the final torque.

 

they probably didnt start the threads by hand, instead they just gunned them on. what we do at sams club is start every lug by hand, and make sure it goes on about 4 or 5 threads. then we gun them on with torque sticks. the torque stick we use for a 21mm lug nut is supposed to stop at 80 ft-lbs, but i know that it goes over because when we torque them with the regular torque stick by hand, it clicks instantly. it does stop, however, around 90, because when we get vehicles that need 100 ft-lbs the lugs do need a bit more snugging before the torque wrench clicks.

 

Ben, thanks for correcting me - I was referring to the torque sticks that Discount/American Tire uses on their air guns.

 

Well they don't do that at every Sam's! At the Scottsdale location they spun one of mine on incorrectly and cross-threaded the thing all the way in. Lucky for me I rotate my own tires and found out that way that I could not get it off. I took it in and told them, they paid the $50 charge for the new stud. It was on our Accord.

At least they took care of it I guess.

 

ya sams is pretty damn good about paying for their mistakes. all sams are REALLY cracking down on the "10 steps to a tire install" my shop now has this HUGE poster inside our shop with the 10 steps. one of the steps specificly says "start each lug by hand"

 

That's good to hear. I tried to talk to the manager about "continuous improvement" or retraining one of the techs, and he blew me off and said it happens every now and then

Anyway, I hope that poster goes up at all the Sam's. Good to hear that they are trying to make things better.

 

ya, generally when things like that go around, it goes to every sams club out there. i'd still ask to tighten them by hand. its worth a try