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Discussion in 'The Garage' started by Solodays, Aug 7, 2008.
is this part of the maintenance process, if so what exactly is it?
Well not to sound like a jerk, but it aligns your wheels. In other words, it ensures that when you are pointing the wheel straight, that the tires are indeed following suit and not pointing off slightly to the left or right.
I don't know what maintenance process you speak of, but if you notice your call pulling to one side of the road then this will more than likely solve that.
ya, thats what i thought too, but not sure, i didnt know wheels need align checks up, WTH? i never heard of such a thing until i saw an ad on tv the other day. my parents honda had like over 90k miles on it and i dont think they ever brought it in for an alignment check up. it's been flawless.
how do you know?
flawless until it starts eating tires
Wheel Alignment really deals with driving habit, I think. If you drive carefully and never hit pothole or street corner, it will stay ok for such long time. For instance, my Hyundai Sonata last without any alignment for 7 years/95k miles since it was driven by my parents for 5 years/70k miles, and I drove quite carefully as well.
On the other hand, I drive really aggressive with my Bimmer this day, and I am predicting some alignment might need in near future as I hit number of potholes as well as I've done quite tight cornering.
Potholes and curbs will wreak havoc on your alignment. But just normal driving on good roads will usually result in little, if any, change in the alignment, except as parts of the suspension and chassis parts, like bushings, tie rod ends, shocks, springs, start to wear out and get more
play. Then you need to align to compensate for it and also after any parts like that are changed. Also any moderate crash can knock it out of
Alignment isn't something you really need to get checked regularly. It's more something you get done to fix a problem that develops. Bad alignment just like any other mechanical problem with a car will have symptoms. If you check for the symptoms regularly, then you'll catch that you're having a problem and you can take it in to get it corrected. Some of the symptoms are the car pulls to one side or the other as you're driving, uneven tire tread wear (ie:inside or outside wearing faster then the rest of the tread), vibration in the steering wheel at speed and tire squeal when going around a turn. Those are the major ones I can think of. Some of them coudl be symptoms of other problems with the suspension too but if you take it in to get it looked at they will be able to tell you if a standard alignment will fix the issue or if it's something else.
Since you know so little about cars, it's a good idea to get a check every now and then (once a year or so). The technician will check for worn parts. If there are any, they can be replaced before they start causing a problem or worse, fail.
More than just pointing straight, most if nto all alignments include checking the camber. Which means pointing the tire up and down at a certain degree depending on the car. so instead of / or \ the tire is | or maybe just a little off.
The squealing is how you know you're going as fast as you can. It's a helpful indicator.
I get my alignment checked once a year regardless of symptoms. If something crops up, I'll have it checked in between those times as well.
I wish I knew someone who knew how to align cars properly.
I've taken mine to a dozen places, here and in CA and nobody can align it properly.
What makes you think that your wheels are not aligned properly? Doesn't the shop give you a chart showing the measurements of your car?
your wheel alignment is also what brings your steering back to center after you turn a corner. Caster, camber and tow are all checked. i just found this, hope it helps. http://autorepair.about.com/cs...alinfo/a/aa012201a.htm
I'm going to provide a very simple, visual explanation of what the different parts of an alignment are, since lots of folks really don't understand:
Toe: Look down at your feet. Rotate your toes inward, like being pigeon-toed. When your wheels do that, that's being "toed in". Opposite is "toed out". Most cars' alignment specs will have the wheels VERY slightly toed in, as the rolling force of the car and the little bit of slop in the components will let the toe move slightly, which will let the wheels be straight when moving.
Camber: \ / <--Looking at your tires from in front of the car. You wouldn't want them sitting like that. They should be basically straight up and down. Tires with camber like those symbols would wear the outside edge horribly.
Caster: Picture the raked front end of a chopper, vs a dirt bike. This is caster. You don't want one side to be drastically different from the other. Can cause weird handling characteristics.
All these specs work in conjunction with each other. There is some tolerance in each spec...meaning there isn't just "one" number to set each one on and it's right.
Sometimes a certain vehicle might need to be to the negative side of the camber spec to not wear the tires. Or might need to be toed in more on one side to keep from pulling.
This is where a "good" front end man comes in very handy, as opposed to someone who just sets all the specs in the middle of the range and lets it go.
You've got it (as usual), but because I can't resist going into more detail:
Caster: Usually combined with "trail". Larger caster angles make the steering heavier, but also improve stability as well as increasing the camber gain during cornering, which is positive for handling.
Toe: Actually has more impact on edge wear than camber. Toe-out increases steering response, but also makes the car more twitchy, sacrificing straight-line stability. Excessive toe causes more issues with tire wear than does camber. Most cases of tire edge wear are from incorrect toe and not from camber issues.
Camber: Positive camber (tire leans outward, away from the car) is rarely good. Negative camber (tire leans inward, towards the car) has benefits for cornering as it counteracts the effects of cornering forces on the outside tires. Most cars have very slight negative camber, both to help in cornering and also because having some camber (regardless of whether it is positive or negative) on the steering axle will result in lighter steering effort.
A more detailed explanation can be found here.
And what about bump steer?
Vibration in the wheel and uneven tire wear. It's not horrible, but it's there.
They do give a chart and all, but I don't see how that really matters.
Ackerman steering angle basically affects how your wheels turn in relation to each other. When you turn the inner wheel turns a tighter turn than the outside wheel. To keep your wheels from squealing and excessive tire wear the ackerman angle is designed to make your inside wheel turn more than the outside wheel. AFAIK in most cars this is not adjustable. It's built into the geometry of how your steering connects together (most importantly, the steering arm angle on the steering knuckle).
You really don't need to worry about the ackerman angle unless you're doing significant suspension modifications.
This is a problem usually associated with suspension modifications. I mess around with jeeps and it can be a significant problem when you life a vehicle if it's not done correctly. The easy way to think about is that as your suspension goes through its travel the steering geometry should not change. When you modify the steering (or the steering is poorly designed) this isn't true and when you hit a bump the steering will veer.
Vibration in the wheel isn't alignment. The uneven tire wear could be.