Ok…long message but want to give as much detail as possible. Decent DIYer but steering is my nemesis.
98 XJ. 5.5” lift. Have 2.5” coils and 3” pucks. (Have ACOS, just not yet installed.
Drop Shackle Relocation Brackets and , adl in tear. Measured and confirmed 5.5”. Cross over steering, t case drop.
had death wobble and pinion was -10. Adjusted lower arms and got to -7. Made a huge difference!!
Just installed control arm drop brackets..measured and adjust upper and lower arms per “recommended” lengths
now my angle is negative 1. Also, my front driveshaft has moved out some.
what should I start my angle at and is there enough front driveshaft in diff.

 

Driveshaft length - I'm guessing that's a picture at ride height? Looks fine for now. If you end up needing to do anything with the driveshaft later yea it could be longer.

As far as pinion angle - ditch that completely in favor of your castor angle.

Whats your castor angle at? If this was a pure trailer queen I would entertain the conversation of pinion angle for longevity of the joints but if this is a primarily road driven vehicle the pinion angle comes 2nd over the correct castor angle.

Your castor angle should be -7°~ from straight vertical. (To make that clear the inner C's on the ends of your axle should tilt backwards towards the rear of the vehicle) A good place to base your measurement would be placing your level on the top cap of your upper balljoint.

 

First, thanks for the reply!
yes, that is ride height pic of the driveshaft.
On the angle, I misspoke. The Caster angle is -1. Measuring from the c’s. That’s a the main angle I’m concerned about.
I still get pinion, caster, king, etc confused. But I’m measuring at the ball joints on the “c”.

ill run my lowers in some to see if I can get to -7. Should be close. If not, I can turn my uppers out a bit. In theory, this should also move more of the driveshaft back into the spline??

Feel free to tell me I’m an idiot. Like I said, geometry wasn’t my best subject.

 

Try to aim for an angle around -4 or -5 to reduce vibration and improve differential alignment.

Tutuapp

 

ok, got the angle around 6. Have adjustable arms. With the drop brackets, had to run the uppers all the way in and the lowers out. Took forever, but at least it’s done.
new question..how long are the spline on the front driveshaft? How much needs to be in the yoke? Have a few inches showing

 

Mine steers good now I just fixed a lot of accident damage that occurred just before I had finished building it!

It is a 3.5" lift with caster angle 6-8 degrees, (varies on each side a bit from factory), and pinion angle is about 1 degree from driveshaft

Even though I have more to do, there is now effectively zero vibration at any speed

You should check you driveshaft at absolutely full droop. or whatever situation you are concerned with and measure how much spline engagement there is.

This is just my guess, but I would want minimum of 1.5"

I have all adjustable parts, I really hate poor steering and while mine had a bent LCA bracket, it was a beast to steer (, slammed a curb in wet weather, but no wobble!)

Fixed that yesterday (***** of a job), and I cant believe how good it feels