Silencing a Squeak Is Tricky Business
Question: I have a squeak in my car’s front end that is driving me crazy. It occurs whenever I turn the steering wheel--but it disappears when it rains. I have had the steering and suspension checked out, and the mechanic could not find loose parts. He said the squeak is coming from a rubber bushing. Is there a way to lubricate this thing?
--J.M.
Answer: You can lubricate a squeaky bushing, but you need to be careful about the lubricant you use. You also should be forewarned that finding the bushing may be difficult and getting the lubricant worked into the part may be impossible. And if the bushing is worn out, lubricating it will only hide the problem.
Your squeak disappears when it rains because the water is acting as a lubricant. It’s a good sign, since (1) it indicates that lubrication will solve the problem and (2) if rainwater can get into the bushing, you should be able to get a lubricant into it as well.
Rubber bushings serve an important role in front ends, providing anchor points for struts and stabilizer arms. As they age, they sometimes can develop annoying squeaks even though there may be nothing fundamentally wrong with the bushing.
The squeak you describe is likely to be coming from the upper strut mount bushing, which anchors the strut and allows the strut to rotate as you turn the wheels. It’s a big, black, doughnut-shaped thing at the top of the strut, which is behind the front wheel.
In some cases, there is a steel sleeve running through the bushing or a bearing inside the bushing, either of which allows the strut to rotate freely. The squeak--more often described as a moan--also can occur if the sleeve or bearing binds up on the strut.
If you have a helper turn the wheel, you may be able to hear or feel the exact location of the squeak. Be careful with your fingers.
Once you have located the squeak, you need to lubricate it. Do not use oil or a petroleum-based product, because it will cause the rubber to swell and then to disintegrate. Petroleum-based lubricants include WD-40, Boeshield and a number of other sprays.
You can use two things safely: a silicon spray that specifically says on the can that it is compatible with rubber; or rubber lube, which is sold in auto parts stores and used at tire shops to lubricate the rim of tires being mounted on wheels.
Since the contact surface where the rubber bushing meets the top of the strut is tightly sealed by the bushing, you may have trouble getting the lubricant to the place it’s needed. Generously spray the lubricant into the bushing. You may have to open the hood and spray the top anchor point of the strut. With luck, the silicon or rubber lube will soak down into the bushing.
If all this fails, you’ll have to break down and replace the bushing or live with the noise.
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* Ralph Vartabedian cannot answer mail personally but will attempt to respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, 1875 I St. N.W. No. 1100, Washington, DC 20006, or e-mail to Ralph.Vartabedian@latimes.com.
