It’s time to have the tires rotated on my 2004 Toyota Avalon at the America’s Tire store where I purchased my Michelins. And I am concerned about the techs over torquing the lug nuts and damaging/warping the four new rotors that were replaced several months ago (along with Akebono ceramic pads). The torque specification for this vehicle is 76 pound-feet but obviously other cars have different torque requirements and I can’t believe that these shops adjust their torque guns to accommodate each vehicle’s torque spec. In checking just now I see variations from 45 lb-ft for a 2001 Geo Metro to 407 lb-ft for a 2003 Porsche Carrera GT. So since it is very unlikely that they would take the time or consideration to be specific for each vehicle, then how can I be sure that they would torque mine properly even if I ask them to? I know that I could purchase a digital torque wrench and check immediately after they perform the rotation but if I found, for example, the torque to be 100, would that be enough to have immediately warped the rotors? Or could the lug nuts be readjusted while in the parking lot by me before driving my car and before the damage occurs?
What is your advice on how to protect from my rotors from being damaged when having my tires rotated. Due to my lumbar spine deterioration I am unable to rotate them myself, plus I want to have the tires re-balanced during the rotation so the work would have to be done at the tire store. Thank you.
These Tire chain store franchises are like fast food franchises.
The same level of experience in their workforces.
If you're concerned about having the lug nuts torqued to spec you're probably better off going to an independently owned repair shop and telling them to be sure to torque the lug nuts to spec.
You'll probably pay a little more at the independently owned, non franchised, shop but you get what you pay for
Thank you for your response.
I have thought of taking it to an independent shop but was wanting to get the tires balanced as well with the service warranty at the tire store that is included in the purchase of the tires. But it may be worth it to go independent as you suggested.
find an independent mechanic you trust, and let him know you want the wheels torqued properly.
It's doesn't have to be perfect. +/- 5 lbs isn't going to make a difference. An experienced mechanic can get pretty close with an impact gun just by feel.
for example, the torque to be 100, would that be enough to have immediately warped the rotors?
it's more about consistency. Obviously they should be sufficiently tight for the wheels not to fall off, but they should all be within around 10lbs of each other. Too tight (~40lbs +) and you risk damaging the studs.
Or could the lug nuts be readjusted while in the parking lot by me before driving my car and before the damage occurs?
heat is what warps rotors, not nuts.
Thank you for your response. So over-torquing the lug nuts does not cause the rotor to warp? I could have sworn that down through the years I have heard that it can. Maybe it’s okay to take it back to the tire store where I purchased the tires because they will rebalance and rotate for free and they will have a record of the service so the tire tread warranty will be honored.
Do the job on your own and save money and worries. So do I.
Read above " Due to my lumbar spine deterioration I am unable to rotate them myself, "
@shadetreecar thanks, @avalon04 I'm sorry, I overlooked it. Do you have a friend or a family member to help you?
Go to a small family shop. Confirm with the tech of correct specs.
Also look where the employees park. If their cars look like not taken care of, skip them. I actually picked a transmission shop this way to install a new transmission. It was two middle aged men and i asked what cars they drove. They both drove late 90s fords and looked well cared for. They were puzzled when i first asked but understood when i explained. They did an excellent job and no issues.
@GT No problem, I appreciate your response. Since I moved to California I don’t have extended family here that I would trust with a torque wrench. 😁
And @shadetreecar thank you for your advice as well.
I found an independent mechanic for my wife’s Accord when I was purchasing transmission fluid at the dealership and ran into a mechanic who was there picking up parts for a customer’s car.
So over-torquing the lug nuts does not cause the rotor to warp?
No, the act of tightening wheel nuts does not warp rotors. Nuts simply clamp two surfaces together. You could probably tighten them until the studs snap off, and the cast iron rotor would still not warp.
Rotors (and other parts) warp because steel has a high coefficient of thermal expansion:
Brakes get really hot.
If the steel in a rotor casting is of poor quality, then it will not expand evenly across the disc, causing it to distort. Even a 2 thousandths of a inch of runout is considered out of shape.
However, if some lug nuts were tightened drastically more than others, and especially if some were loose, then the theory is that when the rotor expands, the imbalanced pressure from improperly tightened lug nuts would cause uneven expansions when the rotor gets hot. Fatigue on the steel as it expands and contracts will also be uneven. The pads will wear out some spots more than others accelerating the wear, and over time the rotor will become "out of true."
Rotors can also warp from standing on the brake after extended braking. The hot rotors will cause the pad material to deposit (bake onto) the rotors. It's better to coast for a bit after extended braking to let them cool off before stopping, or don't come to a complete stop and creep forward a bit.
Thank you for your detailed response. A lot of good information there to learn from. 👍
I have thought of taking it to an independent shop but was wanting to get the tires balanced as well with the service warranty at the tire store that is included in the purchase of the tires.
they should only need balancing once, when the tires are installed. I've never had to get a re-balancing before.
Well I was at least wanting to have the balance check because at some speeds there is a slight vibration. This could be coming from having had all four struts replaced recently as well as the front lower control arms, rack and pinion with alignment. Perhaps after the new parts have “settled “ (for lack of a better term) it needs realigning. ? Anyhow I thought I would have the balance checked first when having the tires rotated to either correct the vibration or to rule out the tires being unbalanced as the cause.
None of those things (steering, suspension) have anything to do with a wheel's balance. A wheel does not BECOME unbalanced. The only reason why a wheel can be out of balance is it was not initially done correctly, or if incorrectly installed weights flew off. Same thing with alignment. Either it was done properly or not. It should not "settle". It all comes down to having the work done by competent people instead of hacks, which is why you shouldn't go to chains. Listen to Jack who's a mechanic.
Vibration could also be a damaged/defective tire or other things.