Tire alignment question

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So I put on new struts, and I suspect I could use an alignment (I used quickstruts of a different brand than what was taken off). I need new tires, so it seems wise to at least check. Before I drop coin at a shop, I decided to look into how to do myself. I've read a few procedures and have the basic idea; but my question is: to what precision do I need here?

For example, if I check camber, and use a 12" level so as to find the distance the wheel is "off" from perpendicular, every 1/16" of an inch is 0.3 degrees (ish). If I found the right specs to my '99 Camry, camber is is -0.14 to 0.1 degrees in the front, and -1.5 to 0.1 in the rear. So to check front camber, I need to be on the order of 0.01" capability, not "within a couple of sixteenths".

Does that sound right? I have a tough time believing I could check that kind of spec. While I have digital calipers, holding a level and measuring the required +/-0.02" seems a bit... nontrivial. OTOH I guess as long as I'm just checking that it is "close enough" it would suffice?
 
Originally Posted By: bdcardinal
http://www.maximummotorsports.com/Camber-Gauge-P192.aspx

You need something like this to check camber on your own.


Thanks, I had seen the Hot Rod link, but didn't check out the tools yet. Not that pricey, but in the description it says "With accuracy better than 1/8-degree..." (or better than 0.125"). So it would just qualify, if I'm not mistaken, in capability.

[I'd also have to measure that the ground the car is on is actually flat; that may require a large level to make sure. A garage floor ought to be level, but as with most things, it's best to measure I'd think.]
 
Supton, I haven't taken my stuff to an alignment shop in years. I do it at home, and don't have near the precision of a gauge. To be fair, camber is one of the more difficult ones to do at home because it's hard to get a perfect level across the tire, vertically, because of the sidewall bulge as the car is parked. I start with getting level as best I can across the tire and using an app on the phone which tells you level (or not) to 0.1 degree. It's probably not terribly accurate, but it should be repeatable. You're looking for about 0* in the front, so you should be able to get it close with the tools you have available. After I set something by hand, I keep a keen eye on tire wear. Wear due to the smallest variance in camber will take a pretty long time to develop, so I don't think it's a big deal in terms of tire life. Camber can have a dramatic effect on how the car handles, though. Negative camber generally aids in stability in corners. Closer to neutral, and the tire can rotate away from its contact patch in the corners and the car will feel less stable.

Toe is pretty easy to set. I have a long 2x4 that I lay against the opposite axle (so if you're doing front toe, the 2x4 goes behind the rear tires). The ends of the 2x4 are graduated with labeled marks each 1/2". I center the 2x4 on the vehicle so I have an equal amount sticking out each side. I have a board with a small laser pointer mounted to it that I lay against the front tire and aim towards the 2x4. I set toe so that my toe "reading" is the same for both tires. It takes some trial and error to find the balance that I want between tire wear and steering response. More toe-in generally means faster steering response (at the expense of tire wear). Less toe-in generally means better tire wear (at the expense of steering response).

Our MDX is generally a very good-handling vehicle anyway, so I don't have a very aggressive front toe on it. Same in the rear -- I don't have much toe-in and I keep the rear camber fairly neutral through the adjustable camber links I installed. I have Michelin Primacy MXV4 tires on it in P235/65R17 size. You may recognize this as the OEM tire for the Honda Odyssey, an application in which owners complain of vary rapid tire wear -- sometimes to the point of being worn in 20,000 miles or less. I'm proud to note that the set on our MDX has about 40,000 miles and still has about 5/32" of tread depth. This is a 4,500 pound SUV.

I'll be the first to say that I've spent MUCH more time messing with alignments myself than I would have if I took the vehicles to a shop, and I've probably spent more $$ as well if I put a price on my time. In return, though, I've learned a ton about how alignment geometry influences how a vehicle drives. You can take a relatively malaise-driving vehicle and really brighten it up with some simple toe and camber settings. You may be doing that at the expense of tire wear, but it's something that you, as the owner, have the ability to do, given the desire.
 
Yes, struts require an alignment.

There are some shadetree ways to get your wheels pointed in the right direction, but these techniques are best used to ease your trip to the alignment shop.
 
The gauge in the link could be DIY easily with a piece of angle aluminum and a level you may already have.

Another idea would be to use angle aluminum and 2 X 4" bolts for the points that touch the rim. Mount the bolts with jam nuts at identical depths and on the top bolt head mount a plumb bob that points to the bottom bolt with a mark on it indicating zero degrees.

Of course you need to get past the whole unlevel pavement issue. Do the setup then after a few thousand miles uneven wear can be felt running a hand over the treads and feeling the wear. If you cant feel it its good enough.
 
Originally Posted By: Hokiefyd
Supton, I haven't taken my stuff to an alignment shop in years. I do it at home, and don't have near the precision of a gauge. To be fair, camber is one of the more difficult ones to do at home because it's hard to get a perfect level across the tire, vertically, because of the sidewall bulge as the car is parked. I start with getting level as best I can across the tire and using an app on the phone which tells you level (or not) to 0.1 degree. It's probably not terribly accurate, but it should be repeatable. You're looking for about 0* in the front, so you should be able to get it close with the tools you have available. After I set something by hand, I keep a keen eye on tire wear. Wear due to the smallest variance in camber will take a pretty long time to develop, so I don't think it's a big deal in terms of tire life. Camber can have a dramatic effect on how the car handles, though. Negative camber generally aids in stability in corners. Closer to neutral, and the tire can rotate away from its contact patch in the corners and the car will feel less stable.

Toe is pretty easy to set. I have a long 2x4 that I lay against the opposite axle (so if you're doing front toe, the 2x4 goes behind the rear tires). The ends of the 2x4 are graduated with labeled marks each 1/2". I center the 2x4 on the vehicle so I have an equal amount sticking out each side. I have a board with a small laser pointer mounted to it that I lay against the front tire and aim towards the 2x4. I set toe so that my toe "reading" is the same for both tires. It takes some trial and error to find the balance that I want between tire wear and steering response. More toe-in generally means faster steering response (at the expense of tire wear). Less toe-in generally means better tire wear (at the expense of steering response).

Our MDX is generally a very good-handling vehicle anyway, so I don't have a very aggressive front toe on it. Same in the rear -- I don't have much toe-in and I keep the rear camber fairly neutral through the adjustable camber links I installed. I have Michelin Primacy MXV4 tires on it in P235/65R17 size. You may recognize this as the OEM tire for the Honda Odyssey, an application in which owners complain of vary rapid tire wear -- sometimes to the point of being worn in 20,000 miles or less. I'm proud to note that the set on our MDX has about 40,000 miles and still has about 5/32" of tread depth. This is a 4,500 pound SUV.

I'll be the first to say that I've spent MUCH more time messing with alignments myself than I would have if I took the vehicles to a shop, and I've probably spent more $$ as well if I put a price on my time. In return, though, I've learned a ton about how alignment geometry influences how a vehicle drives. You can take a relatively malaise-driving vehicle and really brighten it up with some simple toe and camber settings. You may be doing that at the expense of tire wear, but it's something that you, as the owner, have the ability to do, given the desire.


Thanks Hokiefyd; I recalled that you liked to do your own alignment (amongst others here), and wondered if I'd be satisfied doing my own. If I were buying cheapo tires I'd probably not hesitate.
 
I think alignments are worth every penny. They very well could pay for themselves if tires start wearing prematurely.

I didn't hesitate getting a dealership alignment this summer, $99. They did a fantastic job.

My dad (who has done collision repair now for almost 30 years) helped me with my alignment on my Chevy truck. We used a tram bar and it still messed up my new BFG All Terrains. After an alignment at Brake Masters they wore perfect.
 
Originally Posted By: Mr Nice
Unfortunately some techs barely know how to properly use a Hunter alignment rack. I've seen it a few times.


This is really what started me out doing it myself. I was never really satisfied with an alignment job done by others. I've been far happier with my own results than with others'.
 
Originally Posted By: supton
...and wondered if I'd be satisfied doing my own...


I think you have to want to do it. You have to have the desire to learn about it, learn how your car reacts to different setups, etc. It does take some time to get it right.
 
In your case, and many others, I would say a good alignment would be money well spent. All you need to do is find a good shop. Even if you know what you are doing with a couple of the right tools, you won't beat a good alignment rack checking all 4 wheels with someone that knows how to do it, period. Once you figure out you did it wrong, your tires will be toast, and you didn't save a dime. Just finding a PERFECT flat surface is one problem by itself. The best you can do is get it in the ball park. I have a caster/camber gauge, and figured out how to set toe within 1/32, but even then it is not ideal. Just close. There is so much more to it than just camber, and toe. I agree there are too many shops out there that just set the toe, and collect the doe.
 
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Spent some time on this today. I don't know how caster is adjusted, if at all; but camber requires eccentric bolts. So I skipped that for now.

Made up a T-stick, just a 1x2x7' with a board screwed on at about 90 degree angle at about 8 or 10 inches tall. Used rubber cement to attach a measuring tape to the long section. Tuck under car, "hook" one tire edge, use square to find a measurement. Repeat on other tire side, subtract measurements, find toe. Precision it's not, not on a dirt driveway. Rear toe was 2mm in, front was 6mm in. Spec (from what I can tell) is 4mm +/-2 in the rear (so ok), +/-1mm in front (so way out). Busted loose the tie rods, turned the inner a full turn on each side, took out for a spin. No bad handling (above what it has). When I parked I backed in like I always do, but then pulled forward again. This time I measured 2mm toe in. Good enough for today.

I checked on my other Camry, and measured 1mm toe in. So the method can't be too far off.

I like the idea of a graduated 2x4 and a laser pointer, but I haven't figured out how to make it repeatable enough (laser pointer centered in a board that is properly parallel cut).
 
Originally Posted By: Ethan1
Yes, struts require an alignment.

There are some shadetree ways to get your wheels pointed in the right direction, but these techniques are best used to ease your trip to the alignment shop.


It depends. My camry doesn't have any factory provisions. The strut-to-knuckle bolts are round (eg not elongated) as are the top strut mounts. The factory engineers seem smug that their laser welded unibody is very repeatable and shouldn't need tweaking. To do so would probably require cam bolts.

My 3rd gen firebird, OTOH, had camber slots in the upper fenders for the strut mounts.
 
Originally Posted By: supton
I like the idea of a graduated 2x4 and a laser pointer, but I haven't figured out how to make it repeatable enough (laser pointer centered in a board that is properly parallel cut).


The laser pointer's mounting isn't critical. The laser pointer is just mounted to the flat face of a 2x4 that's long enough to span the tire's diameter (25" or so in your case), and parallel with the length of the 2x4. You hold the rear flat face of the board against the tire (so the laser pointer is on your side of the board) and aim the laser pointer towards the rear graduated measuring stick. I mounted the laser pointer in the center of the 2x4 and keep that laser pointer more or less centered on the wheel hub, so as I get the laser angled slightly down to the graduated measuring stick on the other side of the vehicle, I make sure the laser pointer is still directly above the hub center of the wheel.

The actual measurement at the rear is not important. What's important is consistency with the other side. This doesn't measure the total amount of toe (that's done using your method noted above) -- this ensures that each tire's toe is equal to the other side, to reduce the chances of an off-center steering wheel. If the steering wheel is slightly off-center, I'll use this method to decide which wheel to adjust. If the steering wheel is slightly left, for example, then either the left wheel is toed-in or the right wheel is toed-out. Either side could be the right side to correct, depending on what the laser tells you. Without the laser, it's hard to know which side to address.

I've used this to fix just about every "professional" alignment I've had in the past...which is why I've stopped paying for "professional" alignments. Nothing against those who really know what they're doing with an alignment rack...just an observation that you and your peers are very hard to find!
 
I swapped out the struts and new wheel bearings in my Accent. I got it aligned but it was barely out of spec. The struts do bolt in to fixed locations so there is little you can do about the camber short of eccentric bolts. Nothing you can do about caster except slide the subframe forward.
 
Did a rotation the other weekend, thought I had a tire wearing funny--probably because they were used tires, but what the hay, might as well have a shop look at alignment and see how off I was. Looks like I shoulda gotten laser pointers. Toe off up front, but the big problem was thrust angle was off / steer angle. Have to try harder next time.

 
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