Dear Tom and Ray:

I recently drove my girlfriend's sister's car from Seattle, Washington to Salem, Oregon, as a favor. I would have found some way to back out if I had known what I was getting into; the car was a bomb. Although it was a 1981 Toyota Tercel, it looked twice its age. It was filthy inside and only half the things on it worked. For example, the gas gauge worked, but the temperature gauge didn't. The car's worst problem was the right rear wheel, which bounced up and down when the car went too fast. My husband, who had to follow me for a few miles in another car, said the wheel looked like a basketball. My girlfriend told me that her sister's mechanic said it was safe, as long as no one drove over 55 mph. My question is what was wrong with the wheel? And how dangerous was it for me to drive 250 miles from Seattle to Salem?
Nori

TOM: Gee, Nori, relatives sure are a pain in the butt, aren't they? And you think you have it bad...look what I have to deal with.

RAY: Oh stop complaining. If it weren't for me, you wouldn't be writing a newspaper column. You'd still be driving that manure spreader.

TOM: I happened to like my '74 Chevy!

RAY: Well, Nori, the part most likely to cause that kind of bouncing is a bad shock absorber (on this car, it's called a strut). When you hit a bump, the wheel bounces up and compresses the spring. And when a spring is compressed, what it wants to do is un-compress. Then the weight of the car makes it compress again, and it wants to keep going like that....boinga boinga boinga boinga.

TOM: But if the car's springs were allowed to bounce like that, the wheels would also bounce off the ground, like yours did. The strut (or shock) is supposed to stop that from happening. It's supposed to let the springs compress and decompress once, and then keep the wheels firmly planted on the ground.

RAY: And the reason it's dangerous to drive with a bad strut is because if your wheel is bouncing, and is off the ground half of the time, how are you going to steer or stop?

TOM: So have someone check out the strut, and, if necessary, replace it. And while they're at it, there are two other things to check for. One is a bad control arm. These Tercels were known for rusted control arms. And in fact, Toyota has been replacing them for free. A rusted control arm could also be dangerous, because it holds the bottom of the strut to the car, and keeps the wheel assembly from collapsing.

TOM: Finally, at this point, the car probably has a bad tire, too. That's just a result of all that bouncing.

RAY: It sounds as if you missed a real opportunity to make some money on this trip, Nori. If you were thinking, you would have signed a sponsorship deal. You could have painted a big sign over the right rear wheel-well that said "Official Tire of the NBA."