I was wondering if there was a way to measure caster without putting my jeep on an alignment machine?

 

You can use an angle finder. I have one but I have no clue how to use it so i can't be more help. Lol!! I'm sure someone can explain where to mount it. Maybe post pics.

 

Not really.
The only way to know for sure it to have it measured on the alignment rack.
While still on the rack, compare it with an angle finder to some spot on your axle. From then on you can track what it is by how much you have changed it.

 

^^^good idea! Mine is going in for an alignment soon so ill will see if the shop will let me mark it with my angle finder. Of course, I am correct in thinking that caster won't change unless you manually adjust the adj control arms. Right? It's not like toe which can go off after slamming into things.

 

Factory caster is 4+* (back). Factory pinion up tilt is 2*(up or forward) for 6* of separation. Measuring your pinion angle (at the flange) will tell you your caster angle. 4* at the pinion means 2* caster. 6* at the pinion means 0* caster.

 

You have any pictures to illustrate this? This can be confusing for most, but is the best way to describe. Thanks

 

You say 4° at the pinion, but 4° relative to what?
If you mean 4° from vertical, one would have to make sure all four tires are sitting at the same level plane.

The OP wanted to know how to measure the caster at home. It's not an easy task.

Getting it done on an alignment rack gives a place to start. Then, no matter how the Jeep is sitting, the amount and direction of change when adjustments are made can be tracked by measuring from the pinion flange as mentioned.

 

Sorry for the hijack, but it is a related topic. What is the recommended caster if you have the PR44 Ulimited that helps with caster for higher lifts? I think 4.2+ is about the stock factory setting. Will a more positive caster help with highway driveability?

 

So, If you want 5* of caster the pinion would be down 1*, right?

 

They have a good diagram on their site in this pdf
http://dynatrac.com/pdfs/Choosing_th...using_revC.pdf