[FONT="]Hey Guys,[/FONT] [FONT="]Here’s a simple method of checking toe in that I have come up with. Car is Mikey’s 72 Comet. After the Granada disc brake conversion we did a quickie alignment to get it on the road. Since we had to change from 4 hole to 5 lug wheels anyway we had new radial tires installed on the front. [/FONT] [FONT="]The car had a tendency to wander, no return to center after a turn and had generaly sloppy steering. It was hard to keep in the lanes on the freeway. This was Mikey’s first car and he assumed all old cars handled this way. [/FONT] [FONT="]We borrowed an alignment gauge and checked the caster and camber. It had negative caster, which explained the wandering. The radial tires require positive caster as their contact patch is farther back than that of the old bias ply tires. The camber was close to zero, so we didn’t think that was a problem. We set it up with zero camber and three degrees caster. The strut rod nuts were very hard to turn but we finally were able to get them loose. Had to buy an 1 1/8 open end wrench from Sears. Try to find one of those if you don’t have a local Sears or Snap-On guy![/FONT] [FONT="]This didn’t explain why after only two thousand miles the tires were feather worn quite severely on the inside. This is a symptom of incorrect toe-in according to what I’ve read. We had what we thought was about an eighths of an inch of toe measured with one of those commercial alignment gauges last year. When we did another alignment today I came up with a better method of checking toe that is easier and more accurate. See the illustration. [/FONT] [FONT="]Take two eight foot long boards that are straight or metal tubing, channel, etc. Do not use PVC pipe, it bends. The boards have to be perfectly straight and not bend easily. Prop up the boards the height of the axle on either end; I used some old plastic cat litter containers. Push the boards against the tire sidewall. Mark the halfway point (4 feet) on each board.[/FONT] [FONT="]Now for the math, which is simple. Follow along. The toe in is the difference between the front and rear of the tires, in this case (A-B). Measure the diameter of the tire, dimension D. In our case it was 25 inches, close to 2 feet. Now, since the boards are parallel to the tire sidewall and are 4 times the diameter of the tire then the toe in at the end of the boards is (A-H) or 4 times the actual toe in. And at the halfway point the toe in (A-G) the measured distance is twice the actual difference between the tires’ outside edges. Since we can’t measure how far the tires are apart directly as the car is in the way, we can use the difference between the dimension G and dimension H. This is twice the actual toe. So just measure G and H and divide the difference (G-H) by 2. Simple, ain’t it. Think it out, it makes sense.[/FONT] [FONT="]We found the Comet had 1 ½ inches of toe OUT. No wonder the tires were wearing so badly. After adjusting for 1/8 of toe in the car seems to handle better.[/FONT] [FONT="]If you see some error in my logic just let me know. It can’t really be this simple to measure toe, can it?[/FONT] [FONT="]John and Mikey in Kalifornia[/FONT]
does a centerline come into this anywhere? how do you figure in for tire (L) being out/in more/less than tire (R)? ..or does this even matter? ......
Centerline? Who gives a #$%^ about a centerline? I should have mentioned another setup factor. Drive the car down the street in a straight line. Note the position of the staleering wheel. I put a piece of tape on the top of the wheel when the car is going straight. When you are ready for the alignment drive the car forward with the wheel at this straight ahead position. The wheels should be equally toed in or out, if the body is straight that is. Now, if the frame is tweaked or the rear axle is misaligned then it is past my area of expertise. John in Kalifornia
don't most people...position the steering wheel where they like it and then line the frontend to that position? what adjuster is being used to correct the alignment?
Toe is adjusted with the tie rod adjuster sleeves. You can adjust the steering wheel position after setting the toe by removing it and putting it on as close to the center position as possible and then adjust the tie rod sleeves on opposite sides the same number of turns (one in and the other out) until it is perfect. It is always best to adjust the toe in relation to chassis center.
When I did my disc brake change, my toe in was WAY off. I got the wheels straight, measured the front of the tire and the back of the tire. adjusted it tillit was about 1/8" in and tookit to an allignment shop drives great now $40 well spent
The best front end alignment I ever got was alighted with a 1x2, framing square and a string...the tires almost dry rotted before they wore out.
Tried the Comet on the freeway, stays in the lane now. With front and rear swaybars it doesn't lean in turns, either. When we put on the discs we had to change from 4 hole to five and put on some "Hankook" or some such radials on the junkyard "new" wheels." With the old bias ply tires on the back it might have an oversteer problem if it wasn't so gutless with the six. Motor is tight and quiet though so we are leaving it in. Mikey wants a V8 but this only had 68 thousand on it when we got it. Too bad the head and intake are one piece, it could be a lot faster. The best thing one can do for handling is put on a bigger front sway bar. The rear really isn't needed but they came as a set off Ebay. One of these days we will change out the rear for a 5 lug and then new radials for the back. For now it's good enough for a go to school car. John and Mikey
i agree it is worth the money if you can find a shop to do it right, unfortunately i spent several months and pairs of 100 a piece tires before finding a shop that could handle this "basic" task....... whenever i find a good alignment shop i try to stay with them.
I have my own caster/camber & toe gauges, slip plates. I use a laser to level the car. Has to be level front-to-rear and side-to-side within 3/16" for the caster/camber gauge to be accurate. Nice to be able to adjust at your convenience. You need to find the centerline of the chassis and base the alignment off that or the car could end up "crabbing" down the road (wrong thrust angles). By taking some very careful measurements of my car's suspension points I have accurately found the front and rear centerline points. I just drop a plumb line from these points to the garage floor and take my toe measurements from there.
Before taking a steering wheel off and centering it, you should count the number of turns from lock to lock. Then split the number. The steering box is now centered. If it is not centered there is more play in the steering box while you are turning. Also you will find that your signal lights will cancel too soon in one direction and too late in the other direction.
I have just had my front end (steering and suspension) completely rebuild and aligned to my specs. The car handles as well as I could have hoped for. It now turns corners like it is on rails - more than my back can handle. My specs are: Camber: -1.5 degrees +0/-.5 Caster: +3.5 degrees Toe in: 1/8" I have power steering so the added caster is not a problem and it keeps the car straight until I want to turn it.
That make no sense at all. I don't think there is a car out he that uses negative camber regardless of the tire type, it would be a bear to drive. You should always center the steering wheel by adjusting the tie rods. By just moving the steering wheel you will limit your turning radius to one side. Think of it like this, if the steering wheel is a quarter turn left and you are going straight (assuming the wheel is positioned correctly as it was when new) then your steering box is turned slightly also. By adjusting the tie rods you re-center both the box and the wheel. You can check to see if the wheel is on the column properly by looking at the end of the shaft. There are hash marks on the wheel and the shaft that should be lined up. The canceling cam is positioned by the wheel so it would continue to function properly as long as the wheel is centered.
