Caster alignment-NEED HELP !

Hello guys, I’m new to this forum and I need advise !

I have a 2001 XJ and I installed a 3” Skyjacker lift about three years ago along with 31” tires. When I finished the installation I took it to 4wheelparts for alignment (I figure they’ll know what they were doing). After the job was done, everything was within specs, but when I took it out I notice a pull to the right that it did not have before.

I went back, and they said they could not do anything about it because the left-side caster is at its minimum and the right-side caster was maxed out. I was very concerned about the pull because I though it will cause abnormal tire wear. Their response was that the alignment was OK, and that the pull should not cause any abnormal wear.

After running my XJ for more that 60,000 miles like that and my second set of tires, I’m very convinced that the pull does cause some abnormal tire wear, and I’m just TIRED of the constant pull to the right, specially on road trips.

Now, I’m after a solution, and my research pointed out to adjustable lower control arms. So I got a set of RE adjustable arms. I installed them last week starting with the recommended 16” of length, and then I started adding length to the right side arm and continuously road tested the Jeep and the pull was still there with no signs of improvement. I got to stretch the right side arm up to a little more than 17” and it didn’t help. In fact, at that length, I think I blew something in my transfer case because now there is a rattling noise coming from it. So I brought it back to about 16.5”.

What can I do?, is there something else that I need to check?. I’m a little hesitant to take it back to the shop, because I’m afraid they wont be able to do anything and take my money away !

Please help !!!!!!

hzavarce said:

Hello guys, I’m new to this forum and I need advise !

I have a 2001 XJ and I installed a 3” Skyjacker lift about three years ago along with 31” tires. When I finished the installation I took it to 4wheelparts for alignment (I figure they’ll know what they were doing). After the job was done, everything was within specs, but when I took it out I notice a pull to the right that it did not have before.

I went back, and they said they could not do anything about it because the left-side caster is at its minimum and the right-side caster was maxed out. I was very concerned about the pull because I though it will cause abnormal tire wear. Their response was that the alignment was OK, and that the pull should not cause any abnormal wear.

After running my XJ for more that 60,000 miles like that and my second set of tires, I’m very convinced that the pull does cause some abnormal tire wear, and I’m just TIRED of the constant pull to the right, specially on road trips.

Now, I’m after a solution, and my research pointed out to adjustable lower control arms. So I got a set of RE adjustable arms. I installed them last week starting with the recommended 16” of length, and then I started adding length to the right side arm and continuously road tested the Jeep and the pull was still there with no signs of improvement. I got to stretch the right side arm up to a little more than 17” and it didn’t help. In fact, at that length, I think I blew something in my transfer case because now there is a rattling noise coming from it. So I brought it back to about 16.5”.

What can I do?, is there something else that I need to check?. I’m a little hesitant to take it back to the shop, because I’m afraid they wont be able to do anything and take my money away !

Please help !!!!!!

Click to expand...

first mistake - 4wheelparts, ill buy parts from them, but i would never let them touch my rig - lesson learned.

*most* times you want the control arms to be the same legth - what UCA's are you running and are they out of length?
your sure that the alignment is set at 0* toe (everyone has a different number, you might want to play around with this)?
is your axle centered under the rig with a proper length trackbar? (sometimes this can have an effect, especialy on the steering)
is your steeringwheel center?

personally, i wouldn't have 4wheelparts do an alignment, or balance tires, or install my lift........hell there tech was just flipp'n burgers the week before.

what i would do and have done myself is find an alignment shop.....NOT a tire shop like discount or big o.......but a dedicated alignment shop.

on the lower control arm bracket (body mount) you will see two bolts/nuts facing the rear wheel. thoses nuts are attached to an adjustable bracket. between that bracket and control arm mount shims are placed to push or pull the lower control arms, thus setting your caster up or down by degrees.

the adjustable lower arms will work the same way but it only takes like a fraction of an inch to change your caster by degrees.
if one of the control arm mounts is out of alignment with the other....cranking on one arm more or less then the other is just playing hit or miss.

find a shop that can do the work and take all guess work out of it.

I installed the lift myself, and now I know what a mistake was to take it to 4wheelparts (“Experience is the best teacher”)

To answer some of the questions:
1)what UCA's are you running and are they out of length?
Stock, and as far as I’m know nobody has touched them.
2)your sure that the alignment is set at 0* toe?
Not sure, I’ll have to wait till I get home and see the report
3) is your axle centered under the rig with a proper length trackbar?
I use the track bar relocation bracket that cam with the kit. So far no problem with that, and the axle looks centered.
4) is your steeringwheel center?
YES

It looks that I’m running out of options, and I’ll have to take it to some specialized alignment shop

I dont hink they even knew what they were talking about! There is no way you can have caster on one side maxed out and the other at minimum. Caster from one side to the other is set when they weld your knuckles on to the axle and are always set up equal. It would not matter want you did as you cannot twist the axle to change this. Did you get a print out with the specs on it at all to prove what they said? I bet you they never touched the caster as have never know one place that does. What are your caster readings before you go blindly adjusting arm length not knowing if you are changing the write way or not? Look at my site where I show how to read and adjust it. www.go.jeep-xj.info

another consideration to keep in mind is that if they did set up your alignment properly on the rack (regardless of whether they know what they are talking about or not- the alignment computer tells them what to do) and everything is set to neutral, the crown in the road will cause your vehicle to pull to the right. Roadways are built this way to aid in drainage, and unless the caster is set to help counteract this (by inducing a slight pull to the left) the vehicle will tend to pull to the right unless you are on a truly flat surface.
You didn't mention what type of tires you are running. In 60,000 miles, if you are running agressive mud terrain tires, you can't expect much better than 2 sets- especially if you are running a lot of highway time.

I second Go Jeep- check out his site. You will find a lot of usefull information there.

Gojeep said:

I dont hink they even knew what they were talking about! There is no way you can have caster on one side maxed out and the other at minimum. Caster from one side to the other is set when they weld your knuckles on to the axle and are always set up equal. It would not matter want you did as you cannot twist the axle to change this. www.go.jeep-xj.info

Click to expand...

Caster can be different side-side. I've aligned alot of Jeeps and it is rarely the same side to side. Camber is also not normally adjustable on the solid axles, but it also is rarely the same from one side to the other. Axles are assembled from pieces and while they try to get them perfect(?) sometimes they aren't. Accidents can also affect the alignment of the axle without showing obvious signs.

First thing to do is check tire pressure and circumference. Alot of alignments consist of this. Then see how it drives. Next swap the tires side to side and check again. After that it time to start tweaking the alignment. Camber and caster can be changed using offset balljoints available from Mopar or other. They allow up to 2* I think of adjustment. This will allow adjustment side to side indivdually. Road crown will effect tracking depending on the side of the road. So if it pulls equally either way depending on road crown, it isn't alignment. Its gravity.

They probably adjusted the steering geometry based on the rear geometry. Since you have leaf springs, and have had the axle clamps loose, the rear axle may not be quite "centered" on the locating pins- no worries- is "normal". Then they used the "specs" some lame book gave them for use on a STOCK Cherokee without knowing what they were actually adjusting.

Front end basics:

Stuff you can adjust on a Cherokee:
* Toe in.
* Steering wheel centering
* Front DS to pinion angle.

* Camber is not adjustable.
* Caster itself is not adjustable on a Cherokee, any attempt to adjust caster adjusts the front DS angle.

There are two LCA adjusters, one on each LCA mount at the body. Those have to be adjusted EQUALLY.
Ed: This is one of those irony things. Adjustment of the LCA adjusters adjusts both DS angle, caster and the distance of the axle to the body. If you adjust one LCA one way, and the other LCA the other way to try and "fix" a problem caused when DANA made the axle, it will track funny.

Appearant solution to the problem (or atleast what I would do if I was foolish enough to take my Jeep to an alignment shop and had to fix their work)

Put Jeep on stands. Stands should support the BODY, not the AXLE.
Look at the adjuster/LCA body mounts. Find the old washer marks. Most units appear to come with the bolt all the way to the front of the slider. Loosen the LCA bolts at the body. Remove any funky shims they might have installed and make sure the bolts line up in their old locations. They should end up in the same location on each side.

With the LCA bolts loose, but not sloppy, put the Jeep back on it's wheels. Measure the front pinion to DS angle. it should be Zero!. If not, add or subtract the SAME amount of adjustment to each LCA adjuster. Find the sweet spot and tighten the LCA bolts to 75ftlb.

Check your Toe in. Get a tape measure, and with your wheels pointed straight and the Jeep on level ground. On the front tires... Measure the distance across the back side of the tires. Use easily repeatable points like lugs. If you have MTs take notice of in or out lugs. Repeat measurement across front of tire( same distance from the ground, lugs...).
Calculate the difference (subtract the two measurments). If the front measurement is larger, the tires are toed out. If the front measurment is smaller, the tires are toed in.
Set for 0 to 1/16" toe IN. Use collar in middle of tie link (connects knuckles) to adjust.
The collar in the middle of the drag link (one that connects to steering arm) adjusts steering wheel centering.

Disclaimer:
I haven't done this in a couple days, so some of the details may be missing.
To fill in details, locate a Jeep FSM.

Some additions to that.
Again, you can adjust caster and camber individually and without affecting driveshaft angles.
When measuring toe, mark a specific lug on each tire to measure from. Measure the frt. first, then roll the vehicle forward and measure the same marks on the rr. The reason for doing it this way is twofold. 1.The wheel "assembly" can and usually does have runout. Watch a tire on a balancer some time. Checking at the same place on the tire for both measurements compensates for this the same way most alignment machines do. 2. When the vehicle is moving the tire is consantly deforming due to toe in or out, among other things. Rolling the vehicle forward keeps the deformation constant. If you run with toe in, back up more than one tire rev. and get out and look at the tires. They will look like they are cambered in because the bottom of the tire is being pulled out.

Brian