dr bob

I know what you mean. I'm in the middle of gathering all the bits and pieces of pictures and diagrams for my "alignment for the trigonometrically challenged" guide.

Here are a couple pictures of the camber measurement technique. I spring-clamped a standard 24" bubble level to the assembly for this, with a drill bit as a precision spacer. Thanks go to Captain Earl Gilstrom for that inspiration on the drill bit spacer. Anyway, with my toe-in fixture in the wheel with a bungy cord in the vertical position as shown, the bubble level with the drill bit there will show just the right camber when it's centered. You don't need to know any math-- just center the bubble and you are done. For my 17" wheels with the 17" spacing between the corssbars, the drill size is a common 5/32"

Bill Ball

You can do toe with a pair of "toe-plates" and a tape measures. That requires no lasers and fancy math once you figure the difference required to get toe at 0.25º total over the length of the toe plates. I just haven't tried it yet, and I'm not totally comfortable measuring over the sidewall bulge.
http://www.saferacer.com/toeplw.html
http://www.randys-racemart.com/toeplbyqu.html

Bill Ball

I just ordered a pair of toe plates. Report to follow.

AO

Bill-

That's some great information you've posted there. Sounds like a great Saturday afternoon project!

dr bob

I'm just skeptical about my own ability to see a 1/16" difference between the front and rear of those plates. That's about what you need to get to when you want a quarter of one degree of toe-in. My tape isn't that precise, and in fact the sag in the tape front or rear could toss the measurement. I do like the slots they cut in the plate to hold the tape-- nice touch!

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I'm on the fence about buying the caster plates. I guess I need to do more calcs to see if there's an OK spacer-and-level method that can repeatably predict and measure the slopes and slants needed for a good caster adjustment. I think I have the easy toe and camber methods nailed with the fixture and level as they are.

Bill Ball

dr. bob: Same skepticism here. This site says to air up the tire to eliminate the bulge.
http://www.racerpartswholesale.com/longtech9.htm

There is a laser supplemented toe plate system - $400. They claim 1/60thº accuracy.
http://www.advancedracing.com/toe_plates.php

dr bob

Reading the tech instruction on their toe methods, it seems each is prone to errors due to sidewall irregularities or distortions. In the beginning they want the car race reday, with everything including tire pressures set to race specs. Then we need to pump the tires up enough to eliminate the bulge (can't eliminate that completely) and let the toe plates sit correctly against the tires. Hmmm.

My initial method was based on the laser-against-the-wheel at the bottom of the wheel face, no brackets or holders, and using a 6" level. I couldn't get repeatable results. The next try was with the regular level or straightedge held vertical against the side of the tire front and rear, close to the Kibort method. Sort of OK, but it's too easy to get the reading to change just by where you hold the level against the tire and how much pressure you use. I couldn't come up with a reliable enough holder that would maintain consistent pressure against the tire.

I tried the same method, but spread out the pattern some by holding the top of the straightedge/level at the twelve o'clock position and moving the bottom from side to side to get marks 24" apart. But that's still too sensitive to changes in pressure on the level as I held it against the tire.

Bill told us he's going to be heretical when he suggests that you can get a reliable reading when pressing the level against the tires, and I have to agree. The inconsistent results I saw pushed me to fab the aluminum fixtures. Reliable repeatable results are the goal, and I just can't seem to get them without having the level squared up with the wheel face rather than depending on the variables with the sidewall of the tires. Part of the goal for me is to end up with something where there is minimum chance for operator variables to affect the results. In my amateur opinion, even the toe plates method just offers too many ways that a reading might be affected. I'll be very interested in seeing how the toe plates measure up against your other methods. I've been very wrong often enough.

Emickelsen

Ok, I copied and printed Jim's post so I could read it a work last night. Great work BTW, thanks for the huge effort. Now I feel like i have the worst car in the world though. I know I don't, but my god! Wouldn't it be easier to have someone else do it (IF you could find a good place that is)?

SO. I am going through front tires like gas ('bout the same price to). Huge wear inside. Is that JUST a toe out problem, or a combination of that and suspension issues? (see pic)

Emickelsen

thanks again BTW

AO

Holy Crap! Don't drive on those!

I can say that your alignment setup must be WAY off. Certainly toe, but probably camber too. The Toe check will probably help your tire wear about 90%. Then you'll have to breakdown and do camber.

It would take less than 1 hour to check your toe from very start to finish, even for a total Noobie. Do it tonight.

BTW, what suspension issues are you having? Maybe I missed it...

Bill Ball

I don't think you can get camber far enough off to do that. I agree with Andrew that toe out is your problem. It only takes a degree or two out to do that. As I mentioned above, I saw 2 cars that were that far out this last weekend. This is entirely due to adjusting the toe with the suspension not properly settled.

UKKid35

Are your tyres wearing evenly each side?

Is your steering very heavy?

Obviously it would be very foolish to drive on tyres once you can see the belts, problem is you've gone right through them!!!

Bill Ball

E:

You can try this simplified toe technique. (Simplified in that there is no math, no slip-plates or turntables needed).

1. Park the car a couple of feet from a wall where you have a more or less level area for 40 feet behind the car. Have the steering wheel centered. Mark the ground or put a block in front of the tires so you can return to this spot later in the process if you need to (Actually this only needs to be approximate. The more critical distance is in step 6. You can really start from anywhere in step 1, as long as you do step 6 fairly accurately).
2. Put a laser level across one of the front wheels, horizontal across the middle, beam pointing forward.
3. Mark where the projected laser beam hits the wall.
4. Repeat 2 & 3 for the other front wheel.
5. Measure the distance between the marks.
6. Back the car up 19 feet.
7. Repeat 2-5.
8. The marks in step 7 should be 1" CLOSER together than in step 5.
9. If not, adjust the tie-rod lengths, and repeat 1-7 until the step 8 is true.

For the more precise crowd, the distance in step 6 is 19' 1-3/16", but the error is less than 0.002º.

dr bob

E.: We are going to do a clinic here in Glendale in a month if you haven't resolved the issues by then. Right now I can do camber and toe-in with the stuff I have. Caster will take some more effort without the correct plates and fixtures, and I'm trying to come up with something that a home person could use.

On your car-- You have a severe toe-out problem. It's way too common. I recommend that you take it to an alignment place now, without lifting the car at all and with the old tires still on it, and have it aligned without lifting the front of the car at all during the process. The alignment shop will balk at doing it without lifting, and also at doing it with the old tires on it, but press your case as necessary. Then, take the car home and check for worn suspension and steering parts. OK to raise the front for this. Give attention to tie rods and tie rod ends, steering rack bushing wear that shows up as axial play at the ends of the rack, and rack movement when you push/pull on the wheels side to side. Verify that the wheel bearings are OK too.

If all is well on the suspension parts, only then go ahead and replace the tires. Drive it for 100 miles or so, and if there is any pull at all on a level no-crown road, head back to the alignment rack to let them touch up the caster adjustment. Again, no lifting the front of the car prior to or during the alignment!

If it wasn't so blasted hot in Bakersfield now I'd run up and help you do a DIY alignment in your own garage. Glendale will be high 80's today and cooling towards the weekend. But there's no way I'd consider driving down here on those old tires, even for a free alignment.

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The DIY Alignment program, as I see it, is a way for owners with basic wrenching abilities to tackle this service with confidence that they'll get results at least as good as what we expect (but only sometimes attain) from commercial alignment places. If we did a simple pole right now, we'd find more than a few owners who could quickly relate their own tire wear issues to the picture you shared. It may be that a set of alignment tools needs to be packed up in a transit case, and loaned out for group sessions as needed. I was appalled at the poor alignment I received at a local place recommended by several SoCal928 members, enough so that I started thinking about DIY methods that work. In the first post in this thread, Bill Ball has links to Earl Gilstrom's excellent DIY alignment page, and that should be required reading for everybody in the group.

dr bob

Concurrent posts!

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Or do what Bill recommends.