Toeing in the front tires

What is the easiest way to set the correct toe in for the front wheels?

I just replaced a broken tie rod tube. I ran into a stump in the woods. It was just the right size and in just the right spot to go between the frame and the wheel and snap the tie rod tube. Fortunately, Light eventually dawned on yee old marblehead and I was able to sister on a long socket extension to the broken ends with muffler clamps and got "Rudy" back home for repairs.
Although very rusty, the broken parts did finally come off with lots of propane heat and a long handled pipe wrench. I was concerned from the start about getting the wheel back in the original position so I measured the lenth of the exposed threads on both ends of the tie rod tube with calipers before I removed the broken parts. The theads on the tie rod ends were cleaned with a wire brush and I applied some anti-seize material as a lubricate and rust preventer. I had to start the tube on one end for several turns before I started the other end to achieve the same ratio of exposed threads for the final adjustment. However, when I reached what I thought was the right amount of exposed threads at either end of the tube the wheel did not look like it was in the same location in relationship to the back wheel as the side that was left undisturbed. So how do I determine the right toe in and properly alignment of both wheels to each other and to the rear ones?
Bruce

 

No one has replied to this?

Is there a procedure in the manual? If I did this with just the spec, I's put jack stands under the front axle so the wheels would spin. Then I'd spin each tire and use chalk to put a line around the tread of each tire. Using a tape measure, the difference in distance between the lines front and back is twice the toe-in.

 

Well, when I was a "kid", many moons ago, one of the best frame and alignment shops was 1/4 mi. from my house (up on the corner). The owner's son was heir apparent to the shop. Watched him many times do "Toe In" (we were kids and used to hang out there). On his "alignment rack" he used to jack up the front wheels, spin the right one and spray some "el-cheapo" white lacquer on the wheel. He would then take a "special tool" that was nothing more than a 1/16" sharp pointer with a spring on it and spin it on the white paint, therby making a straight line around the tire. He then took an "alignment rod" that was nothing more than a 1x1" square tube with a fixed pointer on the left and an adjustable pointer (secured by a thumb screw) on the right. He then would measure the difference from front to rear of the tires and adjust accordingly. Simple as He**! Anyone can make one of these and look "totally professional"!

I always thought that if the spec called for 1/16" toe in, that was the amount that the front should "tighter" than the rear. In other words, the distance between the front should be 1/16" shorter than the rear.

 

My service manual says to set the steering end of the bell crank at right angle to the axle. Use a line or a straight edge referenced to the rear tire. Adjust the tie rod until the straight edge touches the front and rear aspect of the front tire. Repeat on the other side same end point with bellcrank pointing straight ahead. Then turn in the tie rods 1/2 turn. Obviously, there are a lot of assumptions made about the rest of the Jeep when using this technique. I like James technique better. AM

 

I read somewhere and it is what I use.

With the wheels off. Remove the brake drums and install them backwards. Use a couple lugnuts to keep them in place. Use the lip of the brake drum as your reference front and back. I have found it to provide a rigid point to use the tape measure. Handy for doing the job alone without a helper.

 

Erik, your Dad's reasoning is dead-on accurate. That is why. Also compensating for slack in the tie rods.
Some vehicles use zero toe-in, I think some full size Chevys.

Castor and camber are the other parts of front wheel alignment. On a 4wd straight axle, castor is built in by the position of the ball joints/kingpins, and castor is built in the same way.
Castor is changed when you use "degree shims" between the spring and axle. If you shim up the front axle for better drivline alignment, you are worsening your castor, which can cause wandering and reduced steering "return to center" (sound familiar?) I'll take steering over a little front driveline vibration. Leave out the shims unless absolutely needed.
Camber can be adjusted with tapered shims between the spindle and steering knuckle.


James I share your sentiments. I hear from time to time someone who took his straight axle 4x4 into the shop for a front end alignment "just to make sure". All that is adjustable is toe in!! And that's easy! The others shouldn't be off unless something is seriously bent! And if they are there isn't much you can do but replace the axle!
I saw a Hot Rod magazine article where they took their hot rod to several different shops for a front end alignment. They had some horror stories, shops that came out worse than when they brought it in, etc, one place didn't even touch it (they had put chalk marks on key points to be able to tell).

 

Dr. Vern rocks.

 

This is pretty cool (and familiar). My grandfather showed this to me one time. His special tool was just an awl or corner of a flat blade screwdriver. After jacking up each side and spinning the tires to make a true mark he pushed the vehicle back and forth a few feet so that the tires would be in the natural position (vs. where they end up when let down from the jack) before taking the measurements on the front and rear of the tire. More important when working on a non solid axle (i.e. 2wd) vehicle.

He said that the slight toe in was to allow for the tires to push back a bit while going down the road. I also think that "testing has shown" that most rigs steer and handle better with the slight toe in.

 

Thank you all for your replies. Looks like I have several ways to check this out. I'll try more than one and see if I can't get double check on the measurement.
Thanks again!