Toe-in question

[B Lake]

I just replaced the tie rods on my Suburban. I've always set the toe-in with a tape measure and fine tuned it by driving and observing tire wear. It seem to work as well or better than most alignment shops.

The spec for toe-in is .24". What I can't find is where is this measurement taken from? Front to back of tire? Some measured distance in front of the tire? Anybody know the answer to this mystery?

[grape]

cut you some boards (need to be about 12" tall) the same length as the height of the tire. then cut a horizontal slot in each end of each board about 1" off of the ground. Have a buddy lay one up against one tire and pass you a tape measure while you measure off the other board on the other tire.

Don't get me started on guys operating computer alignment machines that look at you stupid when you ask them what the machine uses for a centerline. Common practice for those crappy machines to "ASSUME" the rear end is square in the vehicle.........which in a street car is very rare.

[B Lake]

Grape,
That's basically how I do it. The last time I had a shop do a front end alignment, the truck was so out of whack it was dangerous to drive. I took it back and the manager showed me the computer print out that showed everything in spec. I says, "that's nice but the steering wheel is 45 degrees off and it dives for the ditch if I let go of the wheel" He says,"the computer doesn't lie and I'm not going to work on it any more" That was the last time.

I'm no math wiz but I know that .24" from the front to back of the tire is a different angle than .24" measured, say, 10 feet in front of the wheels. I'm just trying to establish the base line from which to deviate.

[JohnC]

Red States:
Find a nice, smooth gravel road or driveway. Drive it forward in a straight line. If it pushes the stones outward, toe out a little more and retry.... when it's right it won't leave any tracks.

Blue States:
Buy a couple of 18" square plates of 1/4" steel. Put a bunch of grease on one and make a grease sandwich. Push one of the wheels over the sandwich and note which way the top plate moves. Adjust toe until it doesn't move.

[Hubert]

Maybe that is 0.24 seconds as in degrees, minutes, seconds. Not 0.24" (inches)

You'll have to do the trigonometry for what ever lenght board you want to use. Unless you use a really really straight board of some reasonable length say 10 ft + it will be hard to measure.

[MTTwister]

John C When I did the Duster, I used a short stack of Glossy magazine pages (No, not Playboy) under each front tire. Cheap version of the greasy plates, and allowed the front wheels rotate.

I would assume that it's 1/4" toe in. Trick is to get each tire 1/8" in , not all 1/4" from one tire.

[B Lake]

Originally posted by Hubert:
Maybe that is 0.24 seconds as in degrees, minutes, seconds. Not 0.24" (inches)
Why didn't I think of that? Makes sense to keep all of the units of measure the same. I could do the math if I wanted to but I'm going to stick with the tape measure and test drive method.

[Billman]

Jack up the front end. Spin the tires while holding a marker close enough to scribe a line completely around circumfrance.

If .24 toe in is what you're looking for, that would be the difference between measuring the fronts of the tire to the rears of the tire.

Similar advice as others have said.

Don't need anyones help...

[grape]

a weak 1/8" of toe in will feel descent at speed, but like others have said you have to run a stringline off of one of the rear tires to get the front wheels pointed straight ahead, ackerman becomes a problem if you don't get the wheels centered. Worry about the steering wheel last after you get the toe set, then just do even turns on the tie rods to center up the wheel. At 180 we run a weak 1/8" of toe out......and i'm used to toe out so that's what all my cars get, the toe in will create a dead spot right at center that i'm not much a fan of.

[autocrosser]

I you jack the wheels up and scribe a line on the tread on both and then set it back down don't forget to run it back and forth to let it settle in. You can then measure scribe line to scribe line on the front and then on the back and that should give the toe.

[B Lake]

Got it set pretty good, just have to get the steering wheel centered up.

While messing around with this, I noticed an odd wear pattern on the tires. The inside edge of both tires looks like it is being shaved by something. The area is about 1/2 inch wide. The surface is smooth and shiny, not a matte surface from running on the ground. Has anyone seen wear like this on their tires? This was already there and not associated with the work I just did. I looked at every inch of the wheel well and can't find any rub marks.