Dear Tom and Ray:

I have a '97 Honda CR-V that has a persistent problem: The front wheels keep falling off. First the left front wheel fell off while turning left at an intersection. Then the right one fell off while traveling 50 mph on a state highway. Luckily, there was a cop behind me when it happened, and he flipped on his lights while I struggled to the shoulder. Finally, a few days ago, the left front wheel fell off again, while I was turning left to go out of my neighbor's driveway. My question is, Are Honda CR-Vs known for this sort of behavior? My various mechanics have claimed there's a design flaw that leaves the weight of the car resting on the lower ball joint at the wheels. Is this in fact the case, and have other CR-Vs dropped a wheel or two?

-- Jerome

RAY: Not that we know of, Jerome. Generally, there are two things that cause wheels to fall off: One, they're not put on correctly (the lug nuts are either not tightened, or they're overtightened, causing the wheel bolts to break), or two, the ball joints fail.

TOM: We're not aware of any defects or chronic problems with CR-V ball joints. In fact, we almost never replace them, and we've been seeing CR-Vs in the shop for well over a decade.

RAY: You don't say how many miles are on the car. And the fact is, any car's ball joints will wear out eventually. So if you've got 120,000 or 180,000 miles on this heap, then yes, it makes sense that a ball joint could break. But that's unlikely to happen twice on one wheel.

TOM: So I'm leaning more toward human error. Rather than ball joints, I'd look instead at the possibility that someone is overtightening your wheel nuts.

RAY: If the wheel nuts are severely overtightened, that stretches and weakens the wheel bolts, which are then subject to failure. Even if only one bolt snaps, the pressure then increases on the others, because now there are four doing the job of five. And before long, another weak one gives out, and the rest fail more quickly.

TOM: The cars that are most susceptible to this are the cars on which the tires have been rotated frequently, over a long period of time. And where the mechanic overtightens the lug nuts time after time.

RAY: So have a mechanic you trust check your wheel bolts, and make sure they're not stripped or stretched. If they show any signs of unusual wear or weakness, replace all of the bolts and wheel nuts on all four wheels -- because if someone overtightened one set, they probably overtightened all of them.

TOM: And obviously, until you know what's causing these failures, you'll want to have your front end carefully inspected on a regular basis so you catch any wear and tear before it becomes catastrophic. That's true for anybody with an older vehicle, but it's especially true for you, Jerome.

RAY: So repeat after me, Jerome: "Fill 'er up, check the oil and double-check my lug nuts, wheel bolts and ball joints, please."