Getting the Bias Out of Tire Alignment
Question: My 1978 Chevette came with four bias-ply tires (Model P155/80D13). I recently replaced them with four radial tires (P155/80R13). The car now pulls to the left. I had the car aligned, which seemed to correct the problem, but after 12,000 miles I rotated the tires, and the car again pulls to the left. Should I have another alignment?--L.L.
Answer: When you switched from bias-ply tires to radial tires, you may have changed the front-end alignment characteristics of your car, because auto manufacturers tune suspension systems at the factory for specific types of tires.
Radial tires have fabric or steel cords that wrap around the tire from sidewall to sidewall, while the cords on bias-ply tires are parallel to the tire tread. Radial tires should wear longer and improve gasoline mileage, but they also can change a car’s handling if they are not original equipment.
Pulling from side to side is usually caused when a car’s wheels are improperly aligned. Alignment involves three types of adjustments. Toe adjustment makes sure the tires are pointed directly forward when the car is in motion and is important in preventing premature tire wear. Camber adjustment keeps the tires at right angles to the the road and prevents them from wearing out on one side. Caster, which is determined by the angle at which the wheel is attached to the car, usually relates to a pulling problem.
A new alignment process that has recently been introduced may help solve your problem. It’s called four-wheel alignment, and it takes into account the position of both the front and rear wheels. That might be especially helpful if your problem is caused by the change in tires you have made.
Q: I purchased a Dodge Ram half-ton pickup truck with a slant-six, 225-cubic-inch engine in October, 1984. My problem is that I get an oil residue in the coolant reservoir, even though the radiator coolant is clear. I have taken the truck back to the dealer several times, but they say they can’t do anything further.--W.M.
A: The “oil” you are finding in your coolant reservoir may be residue from anti-leak sealant, which Chrysler adds to the cooling system at the factory.
The coolant reservoir is an expansion chamber that permits the radiator to be full at all times, which should reduce corrosion by preventing exposure of the radiator to air. So, while the radiator water may look clean, the water in the reservoir may develop a milky white or oily appearance.
Another possible cause of the problem is that antifreeze manufacturers have begun putting additives called silicates into their products; these are intended to reduce corrosion of aluminum parts in newer radiators. The silicates also may turn milky or oily in use.
Q: When I start my 1981 Buick Regal after letting it stand all night, the headlights will come on and then go off without touching the light switch. After driving a few miles, the problem seems to rectify itself. My Buick dealer could not solve this problem because it didn’t occur while he had it.--L.C.
A: Intermittent electrical problems in automobiles can be one of the most frustrating and costly repairs. If you have already had the headlight switch checked, the problem is likely to be caused by a short or open electrical circuit in the wiring system.
Try to determine when the problem occurs, such as during cold or wet days. Also, try to time how long after starting the car the problem starts and when it ends. These should help track down where the problem is located.
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.
