Questions and Answers

Shimmying Lexus SC400 Q. Dear Vincent: I recently purchased a 1995 Lexus SC400 in good condition with what I believe are only wear and tear issues. The car has a very uncomfortable steering feel to it. When driving on a bumpy road, the wheel will steer by itself (shimmy, rock back and forth) slightly as the car rides over the different bumps and holes.

I drive in San Juan, Puerto Rico, where roads are not of high quality, they are for the most, of poor construction and bumpy. A lot of people tell me it is the rack and pinion that is the problem.

However, a mechanic who drove it, not really considering himself a true expert on the issue, and he did acknowledge that he doesn't believe that is the problem. Instead, he thinks it could just be the front end right side "terminal" on the tire. He did tell me to consult a true expert.

Does this sound like a rack and pinion problem? Is it typical on Lexus? I took it to San Juan Lexus and they performed a 20 point inspection on the vehicle, they did find a leakage on the rack and pinion and recommended replacement, however, they did not specify that to be the reason for the shimmying or "rocking back and forth" on the steering, I need to get a clear answer on this.

I would not want to spend hundreds of dollars on something the car really does not need, however, I am desperate to get the problem resolved because it feels very uncomfortable to drive the car like that. It is not a joyful ride yet.

• 1995 Lexus SC400
• V-8
• Automatic transmission
• 89,000 miles
• Fuel Injection
• P/S, A/C, Cruise control
• Rack and pinion

Your Help will be truly appreciated,
Eugene
San Juan, PR

A. I like to start out cheap and work my way up. The first thing I would do is rotate and balance all four tires. There is a good chance that this alone will fix the problem. At the very least it will eliminate them as a possibility. While the car is up in the air, check the tie rods and rack mounting bushings and make sure they are tight and in good shape. Also check the ball joints and control arm bushings for wear. No play at all.

Next thing to check are the front struts. If there are signs of "cupping" on the front tires, then the struts are shot and need to be replaced. Also if there are signs of leakage then, obviously, they need to be replaced.

If the tires and struts look good, park the car on level, solid ground, like a parking lot. Bounce each corner of the car vigorously and see how long it takes to stop bouncing. If it takes more than one bounce, the struts are bad.

The power steering rack, in itself, does not usually cause the steering wheel to shimmy. It is almost always one of the things I have already mentioned.