Axle .... wheel alignment?

[Hedgehog]

I've got a front disk brake axle (Dana 30 ) that is awaiting installation for a very long time. I know how to set the toe, but what I don't know is how to set the toe to "0" to start the process. This should be easy, but I've got so many thoughts on the subject I'm having difficulty moving forward.

 

[Lumpy Grits]

After axle install with tires-Set both axle spring pads on jack stands with the tires clear of the ground. Take a nail and put a mark around the circumference of both tires as close to center as you can. The line has to go all the way around.
Now, measure the distance between the line at the front and at the back of the tire. You want to do this measurement at the half way(hub center)of the tire.
NOTE-Do this with the tires you will be using-
"O" TE is when the measurement is the same front to back.
You want a toe-in of 3/32-1/8 inch(total)on a CJ.

LG

 

[Hedgehog]

But wouldn't both wheels be parallel, even when turned? How do you set then straight ahead or am I obsessing about what is essentially nothing? I know how I'm going to set the 1/8" toe in. I'm not going to use the wheels, I'll be clamping 4' sections of angle iron to the disks. They are nice and straight with no compromises there.

 

[Lumpy Grits]

The dia of you tires will change your toe-in
That's why the TE is set with the tires your gonna use installed!
Just set the TE with wheels 'straight' ahead. 1/8" total is max--
Don't bet on that steel been straight-Doesn't take much for a .030-.050 'bow' from one end to the other.
Hold that nail or pen to the center of the tire and spin the wheel-That's your datum line---
LG

 

[Hedgehog]

Lumpy - The rotors are brand new and straight as can be. I think a reading as good as I'd get on my tires is doable. Sorry I'm stuck on this method. But, I'm not saying that I'm not wrong. All in all it's an easy adjustment if I'm wrong.

I'd mentioned that I was stuck and couldn't seem to get moving ahead. Now I seem to have some motivation and I'm off to the store to get some odds and ends to jump into the project today ..... thanks.

 

[mriplaybass]

I have done toe settings the way you have described. Obviously, you will want to put at least 3 lug nuts on to hold the rotors true, and be sure there is not a ridge along the outer circumference of the rotors that would cause an erroneous reading. I always put something against the rotors and rotate them to make sure that they are true before I start. Like LG says, even if you think your straight edges are true, there could be a slight bend to them, that is why when I do it this way I take my measurement front and rear, then I flip the straight edges 180° and take the measurement again. If you get the same measurement, you know your straight edges are true. It is then a simple matter of getting your front measurement to be 3/32" to 1/8" less than the rear measurement.

 

[Lumpy Grits]

D/30 rotors are not held in place buy the wheel nuts.
This is where your correct wheel bearing adjustment comes into play.

HH-To set your "O" TE the direct rotor measurement will get you started. I have done this with a fresh axle build.
The final setting IF it's to be accurate, has to be done with the wheels on.
LG

 

[mriplaybass]

D/30 rotors are not held in place buy the wheel nuts.
This is where your correct wheel bearing adjustment comes into play.

HH-To set your "O" TE the direct rotor measurement will get you started. I have done this with a fresh axle build.
The final setting IF it's to be accurate, has to be done with the wheels on.
LG

Oops! your right LG! I was thinking of a Dana 30 with drum brakes that I recently did, and that axle required putting the nuts on to hold the drum in place. Too many projects going at once!

 

[Hedgehog]

Another 1/2 started day. I set the front wheels using a method described here. The axle is not installed so working on the setting was easy enough.

Two 4' pieces of straight angle iron. Find the 2' center, attach the angle iron to the rotors with the 2' mark in the center. I used a level to make sure the angle iron was level and locked the rotor down with a "C" clamp (s). I set the rotors as straight forward as possible. Then measured the angle iron at the front and at the rear and adjusted the tie rod until both measurements were the same. Then set a toe in of just less than 1/8" at the front angle iron. "Just less" because Lumpy said 1/8" was a maximum number.

Then when I went to set the front up on stands to remove the axle my hydraulic jack said, "NO" and sprayed fluid all over my driveway ........ ERrrrrrrrrrrrrrrr! So, I cleaned up the driveway and quit. Darn it, its getting hot again. I've still got my HiLift jack to set the CJ on jack stands and a motorcycle jack to help maneuver the axle out and in. Gosh I hate loosing my good old floor jack. It can be rebuilt though, another project.

 

[Lumpy Grits]

Call it a day and have a beer or 12-
Like I said before-Since you'll use the angle iron deal. Measure the dia of your tires and use that spec for the length of the 'iron'.
1/8" TE at 40" dia tire is not 1/8" dia at 32" tire dia.
Better luck tomorrow.
LG

 

[Hedgehog]

Lumpy, I'm not saying you are wrong, but quite a few written examples of doing this use 1/8' @ 2'. But as you said, this will get me started. In the end of it all, the front will checked at an alignment shop. I don't want to scuff my tires to death.