Backing pin & problems with rotor

Hi Guys,

First time poster but frequent listener of Car Talk. I have a question that I hope that I can get a little help. I have a 2002 Hyundai Accent with 147,000 miles. I live in Miami, Fl. I took my car to a national car repair company in March, 2011 because the wheel bearing (left) and CV axles (right and left) needed to be replaced. When the repairman completed the repairs, he failed to place the backing pin (?) back into its proper place. So when I drove, it made this grinding, scraping sound. I took my car back to the mechanic three days later and they fixed that problem. Within less than a week, I began having problems with the car shaking and vibrating when I was on the highway and while I was stopped at the light. When I took the car back for an assessment, thye informed me that the rotor was bad. When I asked him if the problems had anything to do with the failure of the repairman to place the backing pin in its proper place. He denied that the problems were related and tried to blame it on another mechanic. Approximately six months prior to getting these repairs done, I had my brakes repaired by a different mechanic. At that time, my mechanic did not mention any problems related to needing to repair the rotor.

This is tough. You have a couple different issues here, and it’s unlikely they’re related.

It’s hard to blame a rotor warping on anyone. It happens, and if it was turned, rather than replaced at the last service, that was more or less an attempt at getting a few more miles out of it…which you did. They’re not all that thick to begin with, and thinning them more by turning just makes them more liable to warp-age.

I’m not sure what this “backing pin” is you’re talking about. I can’t see how anything there could be at fault, unless it was the split pin designed to keep the CV axle nut from backing out. Thinking about it, that may be what it is, and if that is indeed what happened, then these actually might be related, as the axle slapping around in the bearing may also lead to other problems…like damaged bearings. If they didn’t torque the wheels properly, and clean behind the rotors (if removed) when they reassembled everything. then it’s possible that was part of the problem.

These conditions are almost impossible to prove, though. in all likelihood, you’re going to be stuck with a repair bill.

Find a local mechanic you can trust, and get him to maintain your vehicles for you. Stay away from the chain places if you can…they may seem cheaper, but you’ve just seen how that may not always be the case, and they’re almost always unwilling to admit any wrong-doing.

Chase