TOM and RAY:

I'm a bit of a rarity. I'm 23 and love my Volvo 740. It's a 1991 with 130,000
miles.

While most of my friends prefer sportier cars or big trucks, I couldn't be
happier with my squared-off Swede. However, something weird has been going on
recently. When I'm driving at 55 mph, the car develops a slight vibration. The
vibration appears at about 50 mph and disappears at about 60 mph. The vibration
isn't very intense, and I'm not too bothered by it. I'm just wondering what it
is. -- Josh

RAY: Well, I'd say something is definitely out of balance here, Josh.

TOM: Aside from your taste in cars.

RAY: It sounds an awful lot like a wheel that's out of balance. That's what
usually creates a shimmy at a specific speed.

TOM: Perhaps the last time you followed one of your friends in a BMW up onto the
sidewalk, you knocked off a wheel weight and left one of the tires unbalanced.

RAY: For 20 or 30 bucks, I'd have all four tires rebalanced by a mechanic. And
while you're there, ask him to check for any early signs of tread separation in
the tires, which could also cause a shimmy.

TOM: And by the way, if he can see the air inside the tires when he inspects
them, that means it's time for some new rubber, Josh