Gear Noise Common in Some Models
Question: We purchased a Honda LXi Accord earlier this year. Each morning, there is a loud clank sound in the gearbox as the car is backed out of the garage. The Honda service department told us that it is normal for the car to make this noise. What’s your opinion?--L.J.
Answer: A lot of owners of Honda Accords with automatic transmissions complain about noise when they automatically shift gears, especially when the transmissions are still cold. In most cases, it appears there is no mechanical problem with the transmissions.
Honda transmissions are very different from most automatic transmissions in other cars. Honda basically uses a manual transmission that is converted to automatic operation.
In most automatic transmissions, a “planetary gear” system is used, which features a large gear shaped like a ring with teeth cut on the inside of the ring. The teeth mesh with three or four small planetary gears that rotate inside the ring. At the center of this system is a central “sun gear.” The power from the engine comes in to the sun gear and out through the planetary gears.
The transmission shifts gears by allowing the ring gear to rotate at varying speeds. The planetary gears inside the ring continue to rotate, but at different speeds, depending on how fast the ring gear is turning.
Honda transmissions use an entirely different system. Gears are mounted on a main gear shaft and an opposing countershaft. The gears slide along the shaft and are engaged or disengaged with a shifting fork, much like a manual transmission, except that the fork is controlled automatically.
Manual transmissions usually have a more distinct clunking noise when shifted. The Honda automatic appears to generate the same noise.
Q: I use a chemical cleaner to spruce up my tires, but a friend told me that I could damage the rubber. Is there any truth to that? So far, I haven’t noticed any damage, but now I’m concerned.--K.C.
A: The problem is not the chemical’s ability to damage the rubber but the chrome or paint on the wheel.
Certain chemical cleaners for tires contain acids--such as hydrochloric, hydrofluoric and phosphoric acids--that can seriously damage rubber tires if they are not used properly.
The key to avoiding damage is to make sure the tires and wheel are not still hot from driving when you put the substance on. Some areas of a wheel can hit 300 degrees, as hot as a frying pan. If they are still that hot when you put on the cleaner, chrome can be eaten away almost instantaneously.
The right way to do the job is to hose down the wheels with cold water. Some products also require the use of an alkaline neutralizer for the acid. You must remember to use this neutralizer.
Personally, I wouldn’t think of getting acid-based products near my car. Some tire cleaners do not contain acids. Read the labels carefully and you’ll find one.
Q: We have a 1978 Monte Carlo, and it has 49,000 miles on it. We feel the bumps on patched-up roads and are trying to get a smoother ride. Two weeks ago, we had new tires put on, balanced the front wheels and put on four new gas shocks. It didn’t help. Would new springs help?--F.E.S.
A: New springs would be terribly expensive and would probably not help in the least. New springs might raise the level of the car, but it will only have a minor effect on damping the road bumps. That job is handled by shock absorbers, which you have already replaced.
Ralph Vartabedian cannot answer mail personally but will respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, You section, The Times, Times Mirror Square, Los Angeles 90053.
