Alignment question

[Paulstanfill85]

I have looked through some posts before adding my own, but I wanted to confirm some information about alignments. I had a local offroad shop align mine after I installed upper and lower control arms, SYE, and driveshafts. They did it so well the first time and it drove so straight that I liken it to your child’s first words. It was amazing. Unfortunately, they did not tighten my jam nuts very well and the first time on the trail the arms came loose and started tracking to the driver side. I had them look at it and they screwed around awhile and made it halfway better before I just gave up dealing with them. I expect they farmed out the alignment and didn’t want to say so.

I have 3 inches of lift front and 3.5 rear.


Long story short I have a buddy with an alignment machine, and we figured we would give it a shot. My numbers are as follows:

FRONT

Camber -.7 left -.8 right

Caster 5 left 5.6 right

Toe .1 left .15 right

Cross camber .1

Cross caster -.6

Total toe .25



REAR

Camber -.6 left -.5 right
toe .5 right -.08 right

Total toe .43

Thrust angle .29



Question is this, since the pinion angles are pointing directly at the transfer case correctly and I have some walk, I am thinking that the thrust angle being off and the caster mismatched may be causing all of it. The control arms are clearly not the same length. Once setting the thrust angle and having my caster matching between 5-6 degrees, is there anything else I should be looking at? Ball joints are in good shape, and steering system is a few months old from Rugged Ridge. The control arms are only a few months old as well, so no joints should be damaged. My sole issue is that I am too picky on how straight it drives and I now know it can, so I would like to solve it.

Thanks in advance, you all have been so helpful in the past!

 

[Jerry Bransford]

The arms can't change their lengths by just having loose jam nuts, you would have to unbolt one end and rotate the shaft to change its length.

Edit: Yes double-adjustable arms might go out of adjustment with loose jam nuts.

 

[Paulstanfill85]

The arms can't change their lengths by just having loose jam nuts, you would have to unbolt one end and rotate the shaft to change its length.

My uppers are double adjustable, and are the ones that came loose I pre adjusted them before mounting and then taking to a shop so I don't remember if they are opposite threaded or not. But I do see your point. Could I have just gotten lucky on the road crowns on the initial test drive that didn't show any drift? The only thing that changed was the state of the control arms as far as I could tell. Any thoughts as to what else could be causing it? I can't find any faults in the steering components and the tires are fairly new too. I'd just like not to eat a set of tires and I only use it for trips with my camper that are long highway runs to cool spots. I suppose I could just see if the tire wear gets uneven and if it doesn't then it could be my expectations are too high. Years ago before any lifting I remember it driving so well.

Would that slight caster difference cause a walk? Or the slight thrust angle? I am just not an alignment expert by any means.

On another note, I was asking questions about cooling system issues awhile back and did end up replacing my aftermarket radiator with a Mopar radiator. You were absolutely correct in that it seems to cool better. With the Mopar radiator and thermostat and rust remover used like the Black Magic brakes guy had suggested as well made a noticeable difference in gauge stability.

Thanks Jerry.