‘Chop’ Is Hard to Define, Repair

Question: I have a ride problem with my 1992 Toyota Camry LE. It occurs when I am driving on the freeways at speeds of 50 miles per hour to 60 miles per hour. The car seems to be bouncing up and down rapidly as if the wheels are out of balance. But they are perfectly balanced. Representatives of Toyota have told me that this car has a “firm ride.” But the car oscillates. Could I accomplish anything by changing the nitrogen-gas shock absorbers for standard hydraulic ones?

--G.B.

Question: My brand new Toyota Camry has a defect in its ride. On the freeways around Los Angeles, it seems to vibrate. I tried test-driving another Camry and it does the same thing. I have talked to the dealer mechanics, and they agree there is a problem, but they don’t know what to do about it. Is there any solution?

--E.H.

Answer: Both readers are struggling for a term to describe what their Camrys do on the freeway. Some Toyota experts have a name for it: chop.

Toyota spokesmen say they have not received complaints about the Camry’s ride.

“That vehicle is our bread-and-butter vehicle, our biggest seller,” said one spokesman. “If there was a problem or serious complaints about ride quality, that would be a very big issue here.”

And yet, one Toyota expert said, “We do have a harshness complaint problem.”

Fixing the chop may be significantly more difficult than defining the condition, however. The oscillation occurs mainly on some freeways in the West, particularly in Southern California.

Because of their design, older freeways have developed depressions that can cause some cars to oscillate, depending on their wheelbase and suspension.

The Camry’s drive train is mounted in a sub-frame structure of the unibody. The engine mounts are fluid-filled and are supposed to isolate engine vibration and noise from the passenger compartment.

But under certain road conditions and speeds, the whole drive train can begin to oscillate. The problem is by no means limited to the Camry. A number of other cars with the same wheelbase and similar suspensions have the problem.

Although it is tempting to think the problem would be solved easily with a change in shock absorbers, the Toyota expert said that will not help. As a last resort, you may have to try using a different shock, however.

The oscillation also seems to be worse depending on what type of tire was supplied with the car. Toyota uses five different tires on Camrys. If that easy fix does not work, you might try asking Toyota to swap tires. If the problem exists with one, the other may solve it.

It may seem silly, but you might first try experimenting with different tire pressures. The recommended pressure is in the mid-20s, a very low pressure. Often, mechanics put in 6 to 8 pounds more than recommended.