thoughts about lug nut incident

[mostlymark]

I have a 2006 Subaru Legacy L with about 68,000 miles. My wife and I both live within walking distances from work, so we put a pretty small number of miles on the car.

 

About six months ago, we had all four tires replaced at a local, well-respected shop. Fast-forward six months (and 1,750 miles) to today. My wife was driving on the highway when the car began to shake severely. She managed to get off the highway and find a close shop. They inspected the car and four lug nuts loose on the front left wheel, and the vibration had been violent enough to break one of the wheel studs.

 

Obviously this was a bad situation that could have ended much worse. But I'm confused. No one has worked on the car since the tires were replaced, so it seems like the most likely explanation is that the lug nuts were not properly torqued at the shop. But I would have expected the problem to become apparent in 50 or 100 miles, not 1,750 miles.

 

The shop has volunteered to replace the broken wheel stud and address any other problems free of charge. But was this caused by their negligence? And if not, will the problem repeat? I would hugely appreciate any thoughts you folks might have!

[bluesuby]

I tightened the lug nuts when changing to seasonal tires. Haynes manual said 60 lb/ft. WRONG. Internet search on Discount Tire chart says 89. I made it 90. No problems since.

 

Be sure to use a torque wrench. Harbor Freight often sells an adequate version on sale.

[hybridandy]

I put my stock wheels back on a few years ago and went to the first autox of the season (I have aftermarket wheels and winter tires). I did a full service and torqued the wheels with my craftsman torque wrench to 90 ft/lbs. Car performed fine for the hour and half drive there, the whole event and when I was driving home, started to a get a real bad shimmy in the wheel. I figured I'd destroyed a wheel bearing but turns out, some of the lugs where loose.

 

I know they'd been torqued before I left (I did it myself) but they still came loose. Now whenever I change the wheels, I usually try to retorque them a few days later and sometimes one or two will twist just a little before it clicks. This is the stock Spec-B wheels and McGuard wheel locks.

 

It's possible the shop forgot but honestly, most of them finger start the lugs and then hit it with an impact gun so if they forgot to tighten them (with the gun), you wouldn't have gotten down the street. If they're were almost tight enough, you might get what you experienced where they worked loose over the next thousand miles. It sounds like the shop is being reasonable about it and I don't think you have anything to worry about in the future.