you know what, just finished my 3" lift, set caster at +5.5 via teraflex lowers and my ds looks about the same...I myself am curious to hear what others say

 

I think we are all in the same boat here. I installed my TF 3" 2-weeks ago along w/ full flex arm kit. I got a rear TF D/S the same time as the lift. I also had the same problem in the front end w/ the stock D/S and angle. So I got a TF front D/S, I am now at +1 Castor to get rid of the vibe. I think it is out of balance.... I think I am going to end up taking it to a local shop and have them re balance it.

 

If you decrease positive caster you'll also decrease pinion angle but that's not my point here. Vibes is and here's my 2 cents. I bought this JK with 5000 miles on it and shiney black Crager D window steel 16x7 wheels that looked great in many opinions around here. But even after I changed the tires to Goodyear t/a's there still was a intermittant vibration would come and go every 1/4 mile and at 60 plus mph drove me wild. The wifey couldn't much feel it but I could and was going to take it back to Sam's club for rebalance. I wanted to know which tire was the culprit so first I put the JK up on blocks and and in 4wd and had wifey take it up to speed. What did I see ? Not imbalance but wobbly Crager ripoff wheels and one was so bad it moved the tire around too. The new flat black Procomps are round and perfect. Steel wheels explains a lot to me about vibration I've had over the years and I won't have another. Wanna buy some Cragers-for muddin only? What a lesson----------

 

RIGHT!

 

Assume the factory delivers your Jeep with 0 degree pinion angle. When you lift it you build in an angle of 1 degree plus or minus, doesn't matter and it may be more. Now roll the axel to increase positive caster and you've increased it more. That's why I said decrease the caster and also decrease the pinion angle. I have a 2 or 3 inch bb and posted a pictorial on this a while back. It looks like I got 6 or 7 degrees of caster and I want more but don't want to risk vibe from too great a pinion angle. I want much faster steering response too but when I went from a 7 inch rim to an 8 inch the response actually slowed. DANG!!!

 

Not to get into a pissing match w/ you but what you are saying is not correct.
If you decrease the caster angle you are moving the axle which also raises pinion angle. So decreasing caster increases pinion angle.