Dear Car Talk:
Is it possible for lug nuts to loosen over a period of time (after 2,500 miles) if they were improperly installed?
I had seasonal tires changed at a service location, and about a month later, six lug nuts were missing (four on the right rear and two on the left rear).
The service center is stating that it is unlikely that they are responsible. However, I am hearing and reading otherwise from other sources. -- Barbara
Oh, it's very likely that they are responsible. Someone forgot to tighten your lug nuts or didn't tighten them enough. And that's exactly what will happen.
Over time, they'll slowly work their way loose. Every time you hit a pothole or a bump, they'll get a little looser. Until finally, one falls off. Of course, you won't notice that. Then, a few days or a week later, another one falls off. Eventually (if you're lucky), the car will start shaking, and the wheel will make banging noises as it wobbles around. That's when you check and find out you were one lug nut away from a major accident.
Normally, when we install tires, we'll start by tightening the lug nuts in a crisscross pattern. Then we'll go around once clockwise to make sure they're all tight. It's a simple job, really. It's something shops do many times a day. But doing it wrong can be deadly; it's important to have safety systems in place so no one drives out of your shop with loose lug nuts. That's auto mechanics 101.
Who knows what happened in the shop that day? Maybe the mechanic's battery powered wrench was low on power? Maybe the roach coach arrived, and he had a sudden urge for a tofu burrito and forgot which wheels he'd already tightened.
In any case, I'd let this shop know that, having spoken to other mechanics, you are quite certain they neglected to tighten your lug nuts properly, and it created a very dangerous situation for you. Tell them you hope they will be putting better systems in place with their employees to ensure it doesn't happen again.
In the meantime, let them know that someone else will be tightening your nuts from now on, Barbara.