Front Wheel Alignment

[Hedgehog]

After getting a disk brake front axle, cleaning it up and installing different gears and a TracLock carrier I find myself with an axle with misaligned wheels. After measuring the tie rod on my CJ I did adjust, turning the tie rod, the length to be the same. But since there is no real science in doing that I can't help but wonder how to properly align the front wheels.

The ball joints are tight and I am assuming they are set properly, its the toe in/out alignment I'm interested in. It would be good to get it near enough to get to an alignment shop without damaging my tires.

 

[HackFabrication]

IIRC, I just used a tape measure. Got the tires/wheels as straight as I could and towed it to the shop. But that was only 2 miles.

 

[Hedgehog]

Thanks Hack - Sounds like a good way to start. When I read the alignment chapter in the shop manual all the numbers, degrees and shop speak makes me nervous. Don't know why really, tackling other technical jobs is getting to be almost routine, but some stuff is a little like voodoo for my little brain.

 

[Lumpy Grits]

Toe-in--
Wheels straight ahead.
Lift and sit the axle on jack-stands. Keep axle as level as possible, side to side
Take a marking pen and while holding it at the center of the tread. Rotate the tire to mark the entire OD. Do the same, with the other tire.
From the ground-measure up to the half way point on the tire at the front and the back of both tires.
Now, measure the distance between the lines of the back of the tires and then the front at this half way mark.
You want the front to be about 3/16 of an inch 'closer' in the front, than the back.
Hope this helps some--
LG

 

[Only in a Jeep CJ]

The 3 main measurements or readings are camber (the wheel leaning in or out at the top when viewed straight on), caster (the axis through the ball joints and the lean of this pivot), and toe in/out (the front of the tires pointing in or out as compared to two parallel lines).

Camber is fixed via the inner knuckles and can't be changed easily. If its off, its usually a bent part such as a tube, knuckle, or spindle. Bad or worn bearings can also effect this reading. I have seen shims that are tampered for the spindle and there are also offset ball joints that can correct to some degree. (pun intended)

Caster is also fixed but can be changed with longer shackles and corrected with perch shims. This will effect tracking and return to center.

Toe in and out is the easiest to set and can be done at home.

I use jack stands under the spring plates to raise the tires about an inch of the concrete. I use a few inches of blue painters tape in the center of the tread. A wooden block placed on the ground in front will allow a fix position marker to make a line as you rotate the tire to transfer the line to the tape. I use to do the whole tire and draw a full circumference line, but one short line one works fine.
For measuring, I do NOT use a tape measure as the reading can vary too much based on tip placement, sag/droop/arch, and angle of reading the lines. I use a tool called a tram gauge which is a straight square tube with two longer pointer that extend from sliding bases that can be set via wing nuts. I place a wooden block in front of and behind each tire so when the tram is placed on the blocks, the pointers end up at the mid point of the tires front or rear. Just rotate the tire to bring the line to the pointer.

For small tires, I set about 1/8" toe in and can go up to 3/8s on the larger tires.
Both tie rod end clamps need to be loose for the rod to spin. One is reverse threads so turning the rod will increase or decrease the distance of the tie rod.
Only after the tierod is set is the draglink set to center the steering wheel. A tip is to drive the Jeep and see how off the wheels bottom spoke is fro "6 oclock" position. IF its at 7, drive the jeep straight and stop with the wheel at 7 oclock. Leave key in unlocked position and adjust the draglink till the wheel is correct. It will have some float as going down the road.

 

[Lumpy Grits]

The 3 main measurements or readings are camber (the wheel leaning in or out at the top when viewed straight on), caster (the axis through the ball joints and the lean of this pivot), and toe in/out (the front of the tires pointing in or out as compared to two parallel lines).

Camber is fixed via the inner knuckles and can't be changed easily. If its off, its usually a bent part such as a tube, knuckle, or spindle. Bad or worn bearings can also effect this reading. I have seen shims that are tampered for the spindle and there are also offset ball joints that can correct to some degree. (pun intended)


Caster is also fixed but can be changed with longer shackles and corrected with perch shims. This will effect tracking and return to center.

Toe in and out is the easiest to set and can be done at home.

I use jack stands under the spring plates to raise the tires about an inch of the concrete. I use a few inches of blue painters tape in the center of the tread. A wooden block placed on the ground in front will allow a fix position marker to make a line as you rotate the tire to transfer the line to the tape. I use to do the whole tire and draw a full circumference line, but one short line one works fine.
For measuring, I do NOT use a tape measure as the reading can vary too much based on tip placement, sag/droop/arch, and angle of reading the lines. I use a tool called a tram gauge which is a straight square tube with two longer pointer that extend from sliding bases that can be set via wing nuts. I place a wooden block in front of and behind each tire so when the tram is placed on the blocks, the pointers end up at the mid point of the tires front or rear. Just rotate the tire to bring the line to the pointer.

For small tires, I set about 1/8" toe in and can go up to 3/8s on the larger tires.
Both tie rod end clamps need to be loose for the rod to spin. One is reverse threads so turning the rod will increase or decrease the distance of the tie rod.
Only after the tierod is set is the draglink set to center the steering wheel. A tip is to drive the Jeep and see how off the wheels bottom spoke is fro "6 oclock" position. IF its at 7, drive the jeep straight and stop with the wheel at 7 oclock. Leave key in unlocked position and adjust the draglink till the wheel is correct. It will have some float as going down the road.

The use of longer shackles, is not the way to correct camber and no alignment shop will ever recommend such
You place a tapered shim under the the axles spring pad to bring camber back into spec, if nut'n is bent on the axle.

LG

 

[Old Dog]

I made up 2 pieces of square tube 40" long with a slot sawed in both ends. I than use 2 tape measures to set the toe.

 

[Hedgehog]

Hmmmm, not bad at all! What do you use for a measurement? It feels fairly obvious how to set the wheels parallel, but that's only a beginning. I see that you have your tapes a couple feet from the wheel centerline, both front and rear. How much offset do you use?

 

[Old Dog]

Hedge, the tapes are about 36" apart. I made a mark at the center of each tube to eyeball in the center of the hub. I set mine to have 1/8" toe in, works for me.

 

[Woolyworm]

Clever[emoji106]


Wooly

 

[Hedgehog]

Clever is right, the edge or side of a rotor is always the same and repeatable. At one time I was under the false impression that tires were fairly uniform. As I grow older the more I understand the opposite can very well be true. So, finding the true centerline of a tire can be hit and miss. Not so with the rotor.

 

[Lumpy Grits]

FWIW: I use a section of telescoping steel tubing that I can lock in place.
It has two scribe points(1 at each end). Take the rear setting, and then lock the tube in place and then adjust the front to be 1/8-3/16 closer for the toe in.

Old Dogs, is far more accurate.
LG

 

[73CJ]

I made up 2 pieces of square tube 40" long with a slot sawed in both ends. I than use 2 tape measures to set the toe.

I like simple!

Thanks

 

[Only in a Jeep CJ]

The use of longer shackles, is not the way to correct camber and no alignment shop will ever recommend such
You place a tapered shim under the the axles spring pad to bring camber back into spec, if nut'n is bent on the axle.

LG

I never said it was.

What I said was :
"Caster is also fixed but can be changed with longer shackles and corrected with perch shims. This will effect tracking and return to center."

Caster in the knuckles is "fixed" or welded in place in relation to the axle and when people add the longer shackles it changes the caster angle. To bring it back, the use of spring perch shims or wedges can be used. If its done right an alignment shop will not have an issue with it.

 

[HackFabrication]

I made up 2 pieces of square tube 40" long with a slot sawed in both ends. I than use 2 tape measures to set the toe.

 

[Lumpy Grits]

I never said it was.

What I said was :
"Caster is also fixed but can be changed with longer shackles and corrected with perch shims. This will effect tracking and return to center."

Caster in the knuckles is "fixed" or welded in place in relation to the axle and when people add the longer shackles it changes the caster angle. To bring it back, the use of spring perch shims or wedges can be used. If its done right an alignment shop will not have an issue with it.

I did mis-read what you wrote and for that I'm sorry.
Longer shackles will affect BOTH the camber and caster.
As to shims under the axle pad. Don't use the alum or zinc made ones. They are soft and pound out over time. Go to a drive-line shop that works on semi-trucks, and get the steel ones they use.
LG

 

[Hedgehog]

CJ and Lumpy - I think it's all in the way a sentence is read by the reader. I tend to put to many commas in a sentence, but I want to group thoughts. "Caster is also fixed(,) but can be changed with longer shackles" Reads more clearly to me. No this isn't a lesson or scolding in proper writing technic, God knows I'm no writer, but on first reading I got what Lumpy came away with, on rereading I knew what you were saying.