Tehachapi News

All > Columns > Auto Q&A
Auto Q&A: Decisions, Decisions
Topics:
Posted by editor Mon Jan 8, 2007 16:21:45 PST
Viewed 972 times
0 responses 1 comment Dear Q & A: What’s the difference between car wheels being “out of balance” and “out of alignment”? I almost got in an argument with my neighbor about this. My front tires on my elderly (but in perfect condition) Chevrolet Caprice four door sedan are showing some peculiar wear. The steering wheel doesn’t shimmy, even at high speeds, so I figure the problem has to be wheel balance, but my neighbor claims it is caused by wheel alignment. Who’s right?       — W.T.

Dear WT: Steering wheel shudder usually indicates front wheels out of balance. Wheels needing alignment often signal the condition by “pulling” to one side or the other as you’re driving on smooth, flat surfaces. Depending on how long it’s been since your fronts were aligned and balanced, how many curbs and deep potholes you’ve struck, and the age of and mileage on your tires, you’re probably due for both rebalancing and realignment. An imbalance amount of as little as one-half ounce on one front wheel can cause a perceptible shaking in the steering wheel.

A typical dynamic balancer spins the wheel/tire assembly at about 850 revolutions per minute, which is equivalent to a vehicle speed of 60 miles per hour. Weights are added to the wheel rim to compensate for anomalies as slight as one-eighth of an ounce to get you back to rolling smoothly.

Wheel alignment, on the other hand, adjusts the position of the wheels relative to the road surface, in three ways: First, there’s caster, which tilts the steering axis forward (negative caster); rearward (positive caster);or vertical (neutral). The second adjustment is camber, which controls the angle of the wheels when viewed from the front. A lean outward at the top is called positive camber; a lean inward is negative. The third alignment parameter is toe-in, which controls the forward “aim” of the front wheels. A splayed or outward angle relative to the direction of the vehicle is negative toe (or toe-out). A “pigeon-toed” stance, with the wheels aimed inward, is positive toe (or toe-in). Faulty toe-in that’s as little as one-third of a degree off will drag a tire sideways nearly 30 feet for every mile traveled, making this adjustment very critical on tire wear.

Dear Q & A: Which makes more sense, if you’re going to go RV-ing, getting a motor home and pulling a small car behind it, or getting a travel trailer to pull behind a truck? The object is to be able to get around, once we get to a travel destination, without having to use a big, unwieldy vehicle. A towed car would do just fine, but that means we’d have two vehicles with motors to worry about. But a trailer means you can’t legally carry people in it while you’re traveling, and everybody has to ride in the truck until you stop.                — Mr. and Mrs. J.

Dear Js: On a per-square-foot-of-living-area basis, a motor home costs more to buy and to maintain than a travel trailer. But your local trips, once you arrive where you’re going, should be cheaper using a small economy car than using a truck with an engine big enough for trailer towing. Amenities are comparable in MH and trailer, so that’s not an issue. However, backing a short-wheelbase car behind a long-wheelbase motor home is much harder than backing a long trailer behind a relatively short truck, if that aspect of maneuvering is important to you. To choose wisely, it might be a good idea to try out both packages as short-term rentals before you buy.

Send to a Friend

Report a Violation

Comment From: Blaze

Just for the sake of making an informed decision, it might be worth noting that you can carry passengers in a trailer as long as it is a fifth wheel and there is an audible or visual signaling device that enables the passengers inside the trailer to get the attention of the driver (two-way radios will do).