Alignment and wheel balance – misunderstood subjects that can cost you unnecessarily.
Alignment and Balancing are not do-it-yourself jobs. Even if you’re comfortable doing your own brake jobs, these items require a professional. To be done on anything more than a trial and error basis, correcting alignment and balance problems require expensive, frequently calibrated equipment. But a little knowledge about the basics of alignment and balance will help you converse with qualified technicians about any issues your vehicle may have. Since neither alignment or balance are considered normal maintenance items, remember, if it ain’t broken, don’t fix it! A vehicle that is properly aligned does not need a re-alignment when having a new set of tires the same size installed. That said, here’s the minimum everyone needs to know.
Alignment is basically the angle of the wheels in relation to the pavement and the vehicle as well as how parallel they are to each other. The three measures of wheel alignment are:
“Toe” (as in pigeon toe)
“Camber” (the centerline slant of the wheel and tire in relation to the road)
“Caster” (the centerline slant of axle to wheel mounting points in relation to the road).
A vehicle whose wheels are not properly aligned may wander or pull to one side of the road or the other. Its tires will wear unevenly and need premature replacement. The particular uneven wear pattern is a big clue for the alignment technician as to exactly what is out of adjustment and which direction to change it. If severe enough, misalignment can also stress suspension parts and cut fuel economy slightly. Usually, misalignment happens when parts are knocked out of place or bent by hard contact with a curb, deep pothole, or if the vehicle is in an accident. Other causes include:
– tires not precisely the same circumference due to under or over-inflation
– different size tires on the same axle … a big no-no
– tire manufacturing variations (rare)
– aging of suspension parts …especially rubber bushings
– replacement of suspension parts
– substitution of non-stock parts.
During its normal lifetime, a vehicle that never experiences any of these circumstances should not need to be re-aligned. It’s not something you do just because it’s been a particular length of time or number of miles since it was last done, if ever.
Whenever custom suspension modifications are made, re-alignment is a must. Rear wheel drive vehicles with solid axles … including Sierra and Savana … only need to have front wheels aligned. Any vehicle with four wheel independent suspension will generally need all four wheels adjusted if out of alignment. Note that a steering wheel that doesn’t perfectly center when the vehicle is pointed straight ahead can and should be corrected in the front end alignment process. Brand new vehicles and (especially) vehicles that have just had suspension modifications may change their alignment as the new parts “settle”. Take notice of any apparent changes in alignment on such vehicles after 1-2,000 miles. Most reputable suspension modification shops will offer a free adjustment on their original work after a couple thousand miles, if needed.
Expect to pay $60 to 100 for a quality alignment. Some vehicles may cost more, like Ford trucks with twin I-beam front ends. Make sure whoever does your alignment has their equipment calibrated frequently.
Balance is the even distribution of weight at the circumference of the tire/wheel assembly. An out of balance tire and wheel will tend to bounce and prematurely wear out the tire, shock absorber and other suspension parts for that corner of the vehicle. You’ll feel it primarily through the steering wheel if it’s one of the front tires. If you just had your tires rotated and suddenly feel a vibration in the steering wheel, you can be sure it’s one of the tire/wheel assemblies that’s just been moved from the back to the front that needs re-balancing. On the tire, visual signs of wheel imbalance are cupping or bald spots on the tread at various places around the circumference. You may have noticed a beater driving next to you on the freeway with a grossly out of balance wheel bouncing up and down as much as a couple of inches. It’s rare for even the best, most expensive tires and wheels to be perfectly balanced without a little adjustment.
Every new tire needs to be balanced when installed. This involves clamping small weights to the inner, outer or both edges of the wheel rim. On so-called rimless wheels, adhesive weights are attached midway between rim edges. A tire can become out of balance if it’s removed from the wheel to, for example, patch a flat and is not re-installed in exactly the same position on the wheel, if mud or ice becomes stuck to one spot on the inside of the wheel, if a heavy unbalanced wheel cover is attached after the uncovered wheel and tire are balanced or even from a balancing weight or tire that has shifted a little on its rim. I once found a dead mouse under a wheel cover which caused a slight imbalance vibration in that wheel until I removed the carcass. A tire that refuses to maintain proper balance may have a separated belt due to manufacturing defect or puncture that has damaged the tire and caused a belt separation. Look for odd bulges or depressions in the sidewall as additional evidence of structural failure. Sadly, if you’ve had a belt failure due to manufacturing defects, you’re more likely to have additional failures with that set of tires. A set of stock-size tires from a well-known European manufacturer I once put on a Honda Civic had three out of the four fail due to belt separations during the life of the tread … one almost immediately, one a year or so later and a third with about 20% of the tread left. Obviously, a bad batch.
Expect to pay $10 to 15 per wheel for balancing. Note that some tire stores include the cost of balancing in the price of their new tires. And again … although the need for re-balancing is a little more likely than the need for re-alignment … if your car drives straight and true with no wheel vibrations and your tires aren’t wearing unevenly, there’s nothing to fix. Save your money.