Cracked Rotor on a 2010 4 Runner Limited

Big O put $1800 tires on my vehicle in September. When we picked up the vehicle there was a squeaking sound on every rotation the tire made that wasn't there when we dropped it off. When we brought it back to have them look at it, a manager said that it was likely a shield that had fallen and proceeded to take a crowbar out to the rear tire, wrench it, and told us to drive it. He said if the sound was still there to come back. Well, it made it WAY WORSE! Instead of a squeak it became a heavy thud every time you pressed on the brake. We instantly brought it back in, and they diagnosed it as a cracked rotor. Needless to say, we had them fix it to the tune of $500. After returning home and having some time to think about it, I called them back and insisted the breaks/rotor were in perfect condition when we dropped it off to them to have the tires put on. I told the manager that I had paperwork from Lithia in Missoula, as well as from our mechanic that does our oil changes, to prove it, and that something had to be done to it in the shop. A rotor doesn't just break unless something major happens to it. I asked if the guys that put the tire on could have over tightened the lug nut since the crack was through the hole in the rotor and all they could do is say is that they didn't do it and it wasn't their fault; it was ours. I kept asking how it was our fault if there was no sound when we dropped it off, then all of a sudden there is and now WE have to pay for it? Basically the manager told us tough luck and that it must have been weak metal. I asked him to consider splitting the $500 with us since neither of us felt it was our fault, and he said he thought that was reasonable and that he would get back with me the next day. Well, it is a month later and have heard NOTHING!!

My question to all of you is whether or not a rotor could get cracked in the shop, and if so, how does someone prove this happened? I’ve uploaded photos of the cracked rotor. I would love any input/feedback that you can give.

 

Unfortunately that looks like an old crack, you can see black brake dust and dark discolored metal inside the crack, if it happened that day the metal inside the crack would be fresh bright looking metal, it couldn't get that dark old crack look to it in just one day or less.

I have also changed many 100s of tires in my lifetime and I really can't see how even over tightening the lugs could cause the disk to crack.

 

Well, it did take us 3 months to bring it in from the tire change because our son had the vehicle at college, so he drove with the noise for about 1400 miles. I’m sure driving on it made it worse.

 

That info wasn't mentioned in your OP....but from my many years of experience I still find it hard to imagine just installing tires could cause that crack, the way the rims contact the rotors when the lugs are tighten just couldn't cause that kind of damage to the rotor, damage to the rim from over tightening the lugs however can happen, but usually the stud the lug threads onto would most likely break from over tightening before damage to the rim much less a rotor.

 

I doubt that the shop cracked the rotor. It just happens sometimes due to age. The shop did rip you off though charging $500 to replace a $40 part.