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Shams + Scams | Glossary
In this section I will examine some of the easily performed, or ordinary repair services, that are fairly risk free. They too have their glitches but the problems are less involved and point to fewer trouble spots. They will be mentioned because they are frequent ser vices that are performed with average care. Occasionally, short cuts are taken because they are so easily performed. As viewed by many technicians and mechanics, they are mundane chores. They are per formed every day by all mechanics and technicians to some degree. The risks aren’t too serious with these services but if too many things are left out of a procedure they can result in annoying conditions and poor automobile performance.
THE L.O.F. (LUBE, OIL, FILTER)
The lube, oil and filter should be the most frequent preventative maintenance chore you perform on your car. Engine oil is directly responsible for the lubrication of hundreds of moving parts in an engine. Without frequent and regular changes oil breaks down and becomes thin (loses its viscosity). It is subjected to tremendous heat and pressure. If allowed to become too dirty it can clog an oil filter and affect oil pressure directly. If oil changes are not performed with regularity and with high grade oils, engine wear can be expected to increase in direct proportion to the neglect.
WHEN TO CHANGE THE OIL
When does the oil need to be changed? You can follow the recommended mileage intervals listed in your car owner’s manual. Most all manuals suggest an oil change at regular intervals. But be aware those intervals are a general guideline based on average use. You may not be an average driver. If you commute long distance daily in hot weather, or tow frequent loads, or consistently drive well above the speed limit, then your oil may break down faster than average. Generally, when engine oil turns to a completely black color as shown on the dipstick, it’s time to change it. Fresh oil is usually a dark amber, dark green or dark yellow color. When it’s black, it’s dirty and the viscosity has broken down. Also, as your car gets older, with more miles on the engine, the more frequently the oil should be changed. Cars with mileage over 100,000 miles should have the oil changed every 2,000 to 3,000 miles.
TYPES OF OIL
Engine oil is engine oil, right? Not really. There are differences between the grades, and when you have the oil changed, you can usually pick the grade oil you want. If you don’t specify, you’ll get an “average” weight oil, which may not be what you want in some cases.
Insist on high quality, brand name oil and fluids QuakerState, Pennzoil, Valvoilne, and Havoline are examples of high quality oils. It might cost a few cents more, but the long-term benefits for engine life are increased. The generic ATF (automatic transmission fluid) that most quick stops provide is usually very good quality. Your owner’s manual will have the exact in formation you need when considering any fluid change; the type, viscosity, brand name, etc.
Some manufacturers require that you use SE-quality engine oil when making a change. Some oils are detergent and non-detergent, with the detergent oil being the most popular. You must consult your owner’s manual to find out which is listed.
Different weights or viscosities of oil are used, such as: 5W-20, 5W-30, 10W, 10W-30, 10W-40, 20W-20, 20W-40, 20W-50, 40W and 50W. These relative thicknesses of oil can have an effect on your fuel economy. Lower thickness engine oils can provide increased fuel economy. Higher thickness engine oils are preferred for higher temperature weather conditions. Thicker oil breaks down slower in a hot engine whereas the lighter engine oils might give better gas mileage under moderate conditions. However, lighter weight oils break down faster in a hot environment, which could increase engine wear. You can refer to an oil viscosity chart, which may be available in some parts stores. It will list the oil weights that will provide the best balance of fuel economy, engine life and oil economy, under different temperature and driving conditions.
Oil filters are canisters containing fabric filtering elements. Located inline with the circulating oil, their purpose is to screen out debris and engine particles. Some of the popular filters are Fram (imports), AC- Delco (GM), Pennzoil, STP and Motorcraft (Ford). Most filters screw into a mounting plate located on the engine. They require an O-shaped rubber ring to seal them against their mount. The ring should be coated with a light film of oil before application, and the rule of thumb to tightening an oil filter is to tighten by hand until it stops, then go 1/4 turn farther.
Lube refers to lubrication. The car’s chassis and front-end parts are typically lubricated with grease, usually around the time that an oil change is performed. Some of the lubrication spots would be: the upper ball joints, lower ball joints, tie-rod ends, idler arm, Pitman arm and sometimes the U-joint on cars that have the fittings.
These fittings, or zerks, resemble small nipples and this is where the lube grease is injected, by means of a pressurized gun, or by a hand pump. The tie-rod ends and ball joints have boots or cups that cover the ball-and-socket joints. These cups hold extra grease in this area to provide lasting lubrication. If one of these rubber boots tears or breaks, grime, dirt and sand can contaminate the joint. This causes friction which leads to increased wear or allows water to saturate the joint and cause it to rust. Broken or torn boots should always be replaced. On newer cars you might see front end parts that don't have zerk fittings. These parts are “factory sealed” and don't require lubrication. If the part fails due to wear it's usually replaced as a unit.
BEWARE OF THE GOOD DEAL
A typical advertisement for an L.O.F. special might look like this:
1. Drain oil and fill with up to 5 qts.
2. Replace filter.
3. Lubricate entire chassis.
4. Check all other fluid levels.
So you ask yourself what could go wrong with item number 1? Not much but I hope the mechanic knows precisely how much oil each and every make automobile holds: either four, five or six quarts. If oil is overfilled it increases oil pressure, putting strain on gaskets and front and rear main seals. It could then blow out one of these gaskets or seals and you’d have a serious oil leak and a costly repair involving the replacement of them. It’s a good idea for you to know exactly how much oil your car requires, information that can be found in your owner’s manual.
Next, I would certainly hope that the mechanic uses a box-end wrench or a socket to remove the oil drain plug. Using a crescent wrench strips the bolt plug. I would hope that he also replaces the plug washer, or retainer, if the old one is worn or scored.
Wrong Filter—What could happen in number 2? Well, if the wrong size filter is installed there will be a nice puddle on the floor when the engine is started, and the oil will soon blow all over the underside of the car. If this goes undetected, you could be in for a rapid loss of oil pressure and a major engine rebuild. If oil has splashed on the exhaust pipe you might see and smell smoke when you drive your car away.
The O-Ring—New oil filters always come with a rubber gasket ring. When your old filter is removed sometimes the old gasket sticks to the surface of the mount; it does not come off with your filter. A mechanic might say “what the heck” and screw the new filter up against the old gasket ring and toss the new ring on the floor. It does happen. You paid for that part, didn’t you? Why shouldn’t it be installed? Furthermore, if the mechanic doesn’t take it off and puts the new one on over the old one, the filter won’t seal properly and you’ll have a leak. Oil filters should be hand tightened, firmly, unless the oil filter is difficult to reach which would justify the use of an oil filter wrench. If your oil filter is overtightened, it could crush the housing of the oil filter, or possibly crush the gasket ring. If it was an old ring, it could leak.
No Grease—What about item number 3? The only problem that I have seen in this area is the mechanic’s failure to reach a fitting, usually an upper ball joint, or he lets the pressure gun deliver too much grease which sometimes causes the boot or cup to explode. In either case, he should use care to remedy the problem.
Checking Other Fluids—Item number 4 is where most people are taken. This complimentary check is either overlooked or defined strictly. In other words, to check the fluids means to glance at them to see what level they are at. It doesn’t mean adding them for free. The areas included are: the rear end or differential, automatic transmission fluid, manual transmission oil, power steering fluid, brake and clutch fluid, radiator or radiator reservoir (water), wiper/washer fluid and battery water. They’ll tell you it's low, but if you want it filled, you’ll be charged accordingly for each type of fluid. I know of some people who have been to a major quick stop chain where the advertised $19.95 special totaled out to be nearly $35.00. The sham here is that they weren’t told this up front. They just went and filled the reservoirs without asking and charged them accordingly. To be sure, not all quick stops are like this, but it would behoove you to ask up front just what the special includes and what it doesn’t.
That’s not to say the fluids in these areas are not important. They are. But many of these areas (except for the manual transmission and differential) are easy to reach and you should be able to purchase some brake fluid, or coolant, from your local grocery or drug store at substantial savings and fill the area yourself. Then you’d have plenty of fluid left over for future refills. In fact, changing the oil and filter is a regular maintenance procedure you could easily perform yourself. For tips on how to do this, refer to my section covering this.
Four items are removed and replaced or retightened during an oil/filter change. They are; the filler cap, the dipstick, the filter and the oil pan bolt. I would advise that you check these areas to make sure they were replaced and tightened properly. I would also recheck to make sure that the oil level is at the proper level, and that the oil appears to be clean and of a yellowish-green color, not black. Second, before you turn in the car for this service, note the type of filter on the car, and check to make sure that a different or new replacement of the original filter has been installed on the car afterward. During the hectic, repetitive pace of a quick stop facility, it's possible that the mechanics could overlook these areas, either intentionally or unintentionally. I’ve heard of many cases where the oil filler cap had been left off, or the oil wasn’t filled properly, or that the filter was never replaced. A quick check will save you the hassle of an oily, smoking mess, and quite possibly major engine failure within minutes of picking up your car.
The condition of your tires is directly related to safety. New tires are expensive regardless of the bargain price, therefore most people put off buying them until the last minute. Tires can affect steering response, cornering ability, noise, ride quality, road hazard resistance, rolling resistance, traction and fuel economy.
Any automobile owner can visually inspect his tires for condition and road worthiness. You should replace your tires when they are worn if 2/32-inch, or less tread remains, or the cord is damaged, or if the belt material is showing through the sidewall.
Tread Indicators—Most tires have built-in tread indicators (wear bars) that appear between the tread grooves. Tires that are worn and expose these indicators should be replaced when the bar reaches across three or more grooves. The bars will look like a solid line running across the width of your tire. This means that there is not much tread left and the likelihood of poor handling or a hazardous blowout is increased. If the tire tread sidewall is weathered or cracked, cut or snagged deep enough to expose the cord or interior fabric, this would justify replacing that tire. That goes for bumps, bulges, splits, punctures, cuts, or any other injury it has sustained that appears abnormal.
You might notice a vibration in the steering wheel, one that seems to come and go depending on how fast you’re going. This vibration could mean the tire is no longer balanced because the weight fell off. It could be a front end problem too.
Sometimes a tire will wear unevenly if it wasn’t properly balanced or if the alignment is off. Look at your tires to see if the tread is more worn on one side than the other.
Always try to buy major brand name tires. Goodyear, Firestone, Michelin, General, Uniroyal, and BF Goodrich are examples of good quality tires. Under no circumstances should you purchase lesser quality tires or recaps at high prices, unless you specify this option. If you suffer road hazard damage to one of your tires, you can return to any store of the same chain (with invoice and certificate in hand) and have the repair or service adjusted at that store. It is not essential that you return to the same store from which you bought the tire. All stores must honor the standard agreement, and any store that does not is breaching your contract.
The cold inflation pressures listed on the tire placard provide the best balance of tire life, ride quality and vehicle handling (all under normal conditions).
The higher pressures indicated will result in improved fuel economy. Incorrect tire inflation can have adverse affects on tire life and vehicle performance. Low pressures result in increased tire flexing and over heating. This weakens the tire fabric and increases the chance of damage or failure. It can result in tire overloading, abnormal wear, erratic handling and reduced fuel economy. Too high an air pressure can result in abnormal wear, uncomfortable ride and increase the chance of damage from road hazards.
If a tire is worn on both the inside and outside it's probably due to underinflation. That is how underinflation wears tires on the inside and outside of a tire at the same time.
What about overinflation you say? Overinflation will wear just the middle of your tire, because when it has too much air, it bulges at that point—in the middle. The outsides of your tire might look great but say two tire treads or grooves are worn smooth in the middle of the tire. This would be overinflation and you couldn’t confuse it with underinflation.
Checking—All car owners can check tire pressure with a tire pres sure gauge. Radial tires, in particular, must be checked to avoid the assumption that they “look right.” Even radial tires that are Underinflated often “look right,” but they might be lower in pressure by as much as 10 psi, and you would not know it unless a proper gauge was used. After checking the tires for pressure, reinstall the valve caps. These prevent dirt and moisture from getting into the valve core which could cause a leak.
Tire inflation pressures should be checked at least every 45 days, or when you plan to change the load factor, or take an extended trip. Always check tire pressures when the tires are “cold” (before driving). The “cold” tire inflation pressure applies to the tire that has not been used, or not driven for more than a few miles. Remember that it's normal for tire pressure to increase 4 to 8 pounds per square inch or more when the tires become hot from driving. This temperature expansion is normal. Do not reduce or bleed off tire inflation pressures after driving your car because this will underinflate your original “cold” setting. Exact tire pressure is critical and can wear tires faster than an alignment problem.
Front and rear tires perform different jobs and can wear differently depending upon conditions and driving habits and whether the vehicle is front or rear wheel drive. That is why they should be rotated—moved to different locations of the vehicle to even out the load and wear responsibilities. Awhile back it was assumed that radial belted tires could be crossed or moved to the other side of the vehicle (some of the older owner’s manuals display this procedure). But new research now shows that doing this can flex or twist a tire and cause a “radial pull.” It is now recommended to rotate radial-belted tires from front to back or back to front.
Generally, tires should be rotated every 6,000 to 10,000 miles. Check your tire warranty invoice to see if a free rotation is included in the tire purchase. If you abide by its guidelines, your warranty should be strictly upheld. But this free rotation is often conveniently forgotten by the management of many tire stores unless you mention it to them.
If your tires need to be replaced you should replace them with a similar size, design and make. On vehicles originally equipped with radial tires you will find a Tire Performance Criteria (TPC) specification number molded into the tire sidewall. This indicates that the tire meets certain size, performance and load standards which were developed specifically for your vehicle. It is important that you replace your tires with tires that conform to these standards as closely as possible. Putting on tires that don’t meet these specifications could be dangerous.
Mixing—Don’t mix tire makes when making a replacement. Tires come in bias, bias-belted and radial designs. Always stay with the same design—keep them in matched sets. If your tires are calibrated with the Alpha system you can usually change over to metric with a tire that's near or close enough to duplicate the original. A different size or type tire may affect ride, handling, suspension geometry, vehicle ground clearance, tire or tire chain clearance to the fender well and even speedometer/odometer readings.
In regard to speedometer readings, when you have put inappropriate tires on your car, you could be driving faster than your gauge indicates and vice versa. With smaller replacement tires than original, you could notice decreased fuel economy and blame the reason on some other component on your vehicle. In replacing a single tire it should be paired on the same axle with the least worn tire of the other three, preferably on the front of the vehicle.
Balancing—When purchasing a new set of tires it's best to have them balanced at the same time they are mounted to your wheels. This will guard against uneven wear from the onset. Tires that are not balanced can create many different problems singly or together. Proper tire balance provides the smoothest riding comfort and keeps wear to a minimum. Out-of-balance tires can cause very disturbing vehicle vibration, especially at freeway speeds. Unbalanced tires can result in “feathering,” a graduated wear pattern that goes from bad to worse. Cupping, where small bits of rubber are gouged, and flat spots, are other possible problems caused by unbalanced tires. Once wear pat terns like these begin they only get worse; a balance at this stage will not correct the problem nor slow the wear process. The profile of the tire has already been destroyed.
Tire chains excel in the areas of balancing and alignment Tire stores do more than any other repair facility because in one shop they might do dozens of alignments whereas other facilities man age only a few Why are they experts in alignment and balance To protect their tires, of course An improperly aligned or balanced tire will lead to tire failure, which leads to a free (for the customer) yet costly (for the chain) tire replacement Therefore, it's in their best interest for you to get the best wear and mileage out of their tires.
Balance is fairly inexpensive, but if you’re purchasing new tires, the purchase price should include balancing. The tires themselves could cost hundreds of dollars, and many tire chains like to charge $10.00 to $15.00 per tire additional to spin balance them. Many people just accept that as a necessary evil and pay the price. But if you indicate that you won’t purchase the tires unless the balance is included, it's likely the tire store will yield and throw in balancing for free. They can’t afford to lose the sale of new tires at a price of hundreds of dollars for $35.00 worth of balancing, especially when their competitor down the street might be offering the service for free. Balancing is an expendable item for most tire stores.
Some people believe that rear tires don't have to be balanced, and it's true that the rear tires are not subject to the vibration, stress and load the front tires are, but it's not wise to believe this analogy. When all tires come out of the factory mold none of them are perfectly round.
Some can be off only fractions of an ounce while others might take two or three ounces to put them right. But if I were to see a tire mechanic adding more than three ounces to a brand new tire I would stop him and ask him to try another new tire. Such heavy counter weights when used on a new passenger tire could be an indication of a deformity in the tire mold and that the tire is warped. Large multiple- ply truck tires might take much more weight to balance them but the same rule applies to them as well; too much weight needed would indicate a problem. You can generally assume that the less balancing weight a tire requires the better its profile and mold distribution are.
Valve Stems—Valve stems are usually replaced along with new tires, because their life is usually as long. However, like balancing, stems should be included in the purchase price, although the un suspecting customer is often charged for them.
Many people don’t realize that when they purchase new tires they usually receive a warranty or guarantee. Some tire invoices state the seller will repair, inspect and rotate your tires periodically at no charge. If you pick up a bolt or a nail in one of your tires, the shop where you purchased it's likely to fix it on the spot. This amenity can save you around $10. Even if you have caught that nail miles away there is a good chance that you can make it to the shop that sold it to you. The same goes for a tire rotation. This can be a free and regular service which lets them worry about the condition of your tires instead of you.
Be sure to read and save your tire contracts. Quite often these guarantees are hidden in the fine print, and they are not always brought to your attention when you purchase the tires.
Because tires are so critical to safety, a repair customer is vulnerable to several scare tactics used by tire chains to convince them to buy. Some are subtle, some not so. I know of a service manager who liked to take a regular 8-1/2 x 11-inch sheet of note paper and let it drop to the floor of a customer’s feet. He would then point out that it represented the contact area between his tire and the road surface. He would go on to say that it was the difference between safety and plummeting off a cliff on a wet, slick mountain road.
More subtle is the TV advertising campaign of a major international tire manufacturer that features a tiny, near-naked baby who glides across your TV set on a tire, giggling and laughing, with the narrator saying “When so much is riding on your tires. . .“ Images of a tire blowout at speed, or of your car veering out of control toward an oncoming truck with the kids squabbling in the back seat dance through your mind. Within seconds, you’re signing the repair invoice and plunking down the cash for the best tires money can buy.
To be sure, there are obvious reasons why a tire should be replaced. If a chunk of tread is missing, if the steel belt is poking through the tread, if the sidewalls are cracked and weathered, if the tire is almost bald. These are all obvious indications that a new tire is indeed necessary. But don’t be scared into purchasing a more expensive tire, or one that isn’t needed. Use your own judgment. If you are not a performance driver, don’t be sold performance tires.
To insure that you reap the amenities of a full warranty/guarantee package with a new set of tires, you must keep your receipt (in voice), along with the warranty/guarantee certificate. If you’ve had structural failure on a tire and you can't show proof of purchase, then chances are the store won’t honor its agreement to provide you with repair or adjustment services. It is true that they keep your invoice on file, but this backlog of in voice files are purged some years after your purchase. If you’ve lost your receipt one or two years after your purchase, the store is obligated to find your copy in their filing system so that they can honor the contract. But this search for your receipt amongst their files is something at which they frequently balk. Remember, that if you have lost your receipt (for a tire purchase), you have every right to ask that your copy be obtained from their files. If they tell you that your receipt has been purged (thrown away) after only two years, and that they will not honor the warranty/guarantee on the tires, argue the case. They just might not feel like looking for your receipt unless you press the issue.
Alignment is a catchall word that covers the many adjustments of your car’s front suspension. If you really get into it, you’ll find the science behind it baffling, concerned with technical geometric theory and formulas. And because of this complexity, many people are easily led to believe by shady mechanics that if they’ll just pay for a $70 alignment, then the mysterious vibration or pull will disappear. Quite often, the same problems could be remedied by simply inflating the tires properly or by having a tire balanced (around $10). Let’s see if we can’t make this mysterious alignment business a little less complicated.
The need for an alignment (with a new set of tires), can be a two-edged sword. It is certainly recommended, but it's a service that could be pushed off onto you with the conviction that it's necessary to insure that your warranty/guarantee package is honored. This is not true. An alignment is not mandatory when you have purchased a new set of tires, it's only a safeguard. If your old tires were wearing reasonably we/I (even tread wear), the need for an alignment would be questionable. Ask the alignment mechanic about your need for this service, not the service manager.
Your car’s alignment can be knocked out of whack if you were to hit a deep pothole hard, or smack curb while attempting a difficult parallel parking maneuver. Or, the adjustments can simply come loose with vehicle age. Improper alignment will call attention to itself with a vibration felt through the steering wheel, or, your car may drift to the left or right rather than follow a straight line if you should let go of the steering wheel momentarily. Your tires could also be wearing unevenly, faster on one side than the other.
Other Causes—But before you rush off to the nearest alignment rack, rule out some other possibilities first. Check the tire pressures to make sure they are all set to the recommended setting. Check to make sure all wheel weights used to balance the tires are in place. If you can’t find them, then be sure to ask the tire store to check for them and rule out that possibilty.
What are the exceptions when dealing with a pull? When the pull is not that noticeable, yet the car still turns either way from its straight and intended course, it's called a drift. It could be a slight drift in which the car eventually ends up to the left or right after a while. You might notice a pull in a hundred or so feet of driving whereas in the case of a drift or slight drift it might take you a quarter of a mile to notice it. Both a pull and a drift can be the result of an improper caster setting.
What else could make your car pull or drift? A damaged front end suspension part would. What if you had a grossly underinflated tire on your left front? Since we know that more air in a tire causes it to roll easier we can assume that an underinflated tire would drag. If that front tire was low and dragging it would pull or make the car drift in that direction. A car will pull or drift to the side of a wheel that has its brakes dragging (not to be confused with a brake pull, which happens when the pedal is applied). A car will pull or drift if one of the front tires is damaged, worn or deformed in some way. And certainly a car will drift on a “crowned” road; because some roads are built higher in the middle to assist with water drainage. Since you drive on the right side of the road you can expect that the road will canter to the right or toward the rain gutter. Thus your car might move slightly in this direction while driving.
Alignment is an expendable service for a tire shop. It is quite common for a shop to throw in a free alignment to cinch the sale of four brand new tires if they feel you’re going to walkout the door and go somewhere else. Many customers are unaware of this fact. Your ultimate ploy would be, “Well, I guess I have enough for the tires, but I don’t have enough for the alignment and balance. Throw that in and I can afford it.” You would be surprised how well this tactic works. By visiting several shops with this plan, you’re bound to find one that will give in and make the deal. Managers are well within policy to haggle with this service. They can write it off since it's a pure labor charge. Try it next time!
UNDERSTANDING THE LINGO
Many mechanics will fire a barrage of technical terms your way to confuse and intimidate you into having an alignment done, and to impress upon you that great technical expertise is required and the high charge is justified. The truth be told, the mechanic probably knows about as much as you will after reading about the following terms, more than likely he will know less! Most of the guesswork in alignment is taken care of by a sophisticated alignment rack that can be easily operated. So a quick briefing on the related terms can be to your advantage. These terms can be easily understood if you just think of your feet as the front tires of your car.
Toe—If you have to, go out and stand directly in front of your car with your back to the front bumper. With your feet set slightly apart, in a normal stance, point your toes slightly outward. Now imagine that your front tires have just done the same thing; both of them pointing outwards (away from each other), just like your toes are. Now bring your toes back to pointing straight ahead. Now, point your toes inward as though you were assuming a knock-kneed stance and imagine, behind you, that your tires have just done the same thing. Come back to your straight stance.
When your tires are toed inward (knock-kneed) it's called negative toe-in. One tire can be straight (call that zero degrees) and the other tire can be pointing inward (negative-negative degrees). Just remember that zero degrees or very close to it (toes pointing straight ahead) represents normal in the case of your tires.
Pointing your toes outward (bow-legged) is positive toe-out, or they are toed-out. Out = positive. In = negative. Similarly, you can have one tire positive and the other tire normal (straight ahead). You could have one tire positive and the other one negative. Sort of a half bow legged half knock-kneed situation. You can even turn around facing your car and do this; you will get the same effect.
Get it? You’ve just learned a very important measurement that the mechanic has to make. He wants to point your tires straight down the road (or whatever the specification book says—some manufacturers like your car to go down the road with slightly negative toe). But for our purpose just remember that straight is great.
Many new cars today no longer need the camber and caster alignment adjustment. The front end parts are pre-set with no allowable tolerance. If you do discover from a mechanic that you have a caster or camber problem and that there is no adjustment for it on your car, be prepared to pay for a new part to remedy the problem. How can one of these parts go wrong in the first place? They can be worn or damaged by hard and erratic driving habits. Sometimes, striking a steep and sharp curve at moderate speed can bend a front end component.
How can you tell if your tires are negative or positive toe? It’s kind of hard without the alignment rack but there is a way to look for it in tire wear. If a tire is pointed inward too much (negative toe) it will have a “feathered” wear on the inside of the tire. If a tire is pointed too far outward (positive toe), it will wear on the outside of the tire and only there.
Camber—Things start to get a little more confusing because camber can wear your tires just like a negative or positive toe problem. In fact, camber is responsible for wearing your tires on the inside and outside more than toe does. Could you have a toe problem and a camber problem at the same time? Yes. Let’s go back to the front of the car again. Keep your feet planted flat, then roll your feet so you are standing on the outsides. Visualize if you can that the tire is now riding more on its outside surface than it's on its inside surface. It’s kind of tilted on its edge, isn’t it? Now if it were to ride like that it would certainly wear out the outside edge of the tire because it’s tilted—the tire is not seated flat on the ground. Since it's going to wear the outside edge of the tire it's going to have positive camber wear (just like a toed-out condition would produce positive toe or positive wear). Now roll your feet inward so you are standing on the insides of your feet. This is called negative camber and it would wear the inside of the tire.
Now straighten up and stand normally. Like toe, this is the normal position for your tire to rest on—flat on the ground. This camber measurement is in degrees as well. Can you have one tire with positive camber and the other one negative? Yes, because each wheel has a separate adjustment—most cars are equipped with independent front suspension. It is also conceivable that you could have a negative toe and a negative camber on one tire. If these adjustments were large you could really have a heck of a worn tire.
Caster—There is one more adjustment that you should be familiar with. There is no need to explain the adjustment or position of the tire in this case since it does not normally wear tires like toe and camber. It is called caster. More than anything else (with a few exceptions) an improper caster setting will be responsible for a pull to the left or right while you are driving down a straight and level road. If your car pulls to the left the mechanic makes an adjustment that offsets this discrepancy. The idea is to get your car back into a position where it tracks straight. Caster is normally associated with a noticeable or even a hard pull to either direction. Just remember that caster pulls.
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