CRICKETS..........
Eddie, I know that you are trying to help us out, but I think a lot of us don't understand what caster is, what pinion is :doh::doh: ...and whether the adjustable control arms are used to "spin fwd or spin backward" the top or bottom of the driveshaft to adjust this caster & pinion stuff. I know you're busy, but it would be a HUGE help if you ever have time to do a quick tutorial on YouTube (or even post a detailed drawing here) to actually show us what you are talking about.
A lot of the people you interact with understand this stuff like the back of their hands, but many of us do not. I believe that I am speaking not just for myself, but for many others who want to understand all of this suspension geometry and how the different parts affect it (especially upper & lower, front & rear control arms) not just get advice as to whether we need it. Thank you!!
You ever get a shopping cart with a bum wheel that just wants to spin all over the place? That is essentially what you would see with zero caster. Take a look at the front wheel of a bicycle and if you'll notice, the front forks that hold it is angled to the back. This is what you would see with positive caster and it helps to keep your wheel wanting to go straight even after making a turn. The same is true on your Jeep, your front axle needs to have the back of it dipping down a tad to help keep your Jeep tracking straight especially at highway speeds. If you look at the end forgings on your front axle or what some refer to as the "C's", the top part of them is leaning a bit to the center of your Jeep and that is positive caster.
Below is a link to a write-up I did on how to set your caster using adjustable control arms.
https://jlwrangler.com/showthread.p...NT-END-ALIGNMENT&p=12270&viewfull=1#post12270
Pinion is the part of your axle that is connected to the drive shaft. In the rear, the angle that your pinion flange sits at will be parallel to the output shaft on your transfer case being that it uses rzeppa joints. Basically, a type of CV joint. Here's what it would look like from the factory.
Aftermarket shafts replace the CV's with u-joints and a double cardan at the transfer case end and in order to keep it from vibrating, you need to change the angle your pinion sits at to being parallel with your drive shaft. Here's what it should look like after setting your pinion angle.
Now technically, with an aftermarket shaft up front, your pinion should look something like that as well but that would give you negative caster and your Jeep would drive horribly. Needless to say, up front, caster NEEDS to take precedence over pinion angle.
Does this help?