Setting Caster

[nagal]

Okay this is more about correctly reading caster. I am going to be doing a lot of tweaking (yeah no meth involved) and tuning of my Jeep this weekend. One of the things I want to get set is my caster.

My only concern is either place I do it (my house or a friends) our driveways have a very noticable slope. Seeing as how I need positive caster on my TJ (4-7% depending on who you ask) and the Jeep will be parked point up the slop of the driveway, I should subtract the slope of the driveway from the caster angle reading so I get a true refrence to a flat surface?

Sorry if this seems really simple but my geometry is very very rusty and was never my favorite in school.

[Black & Tan TJ]

Hey Nagal,
Sound good. Let me know how you figure this out, I'm curious about my own. I have the RE adjustable upper arms that are turned in (shortest) most of the way. I've heard the 7% stock but as you lift it you won't be able to or want to have that much, 4-5% is what I've heard is good w/4" of lift. I did find though when I had mine turned out a little more it wanted to wander a bit, now it centers itself with them turned in.

Let us know, this should be a good thread, B&T TJ

[Dukes69]

how much of a slope is the driveway on? Why not jack up one end of the jeep so its level . . . if the slope isnt too steep.

[nagal]

B&T TJ,

I'll keep everyone informed As far as what to set it, if I get anywhere between 4-7 I'll be happy. Too many different opinions on where it should be set. With that said, yeah it is next to impossible to get the factory setting unless you cut off the inner c's and reset. Um, no thank you

Chris,

My drive way is easily 3-5% my friends is not nearly that much but it does slope some. I am hoping he will give me a hand this weekend or at least let me use his driveway as it is a lot more spacious than mine. I like your idea of jacking up the rear to level it. As always, it seems I might have over thought the problem.

[Dukes69]

Chris,

My drive way is easily 3-5% my friends is not nearly that much but it does slope some. I am hoping he will give me a hand this weekend or at least let me use his driveway as it is a lot more spacious than mine. I like your idea of jacking up the rear to level it. As always, it seems I might have over thought the problem.

jack up the front, that way you'll still have the e-brake and tranny holding the jeep. Instead of a 10 year old, 1/2 broke cinder block with black widows hiding it it.

[seapahn]

You mean to tell me you can't find a flat piece of ground anywhere close by in Cali?

[nagal]

I am sure there is plenty of flat ground BUT where I'll be working it isn't. Go figure

[rick]

Make sure you are not confusing % with degrees... 7% in angular terms is 0.07x90 = 6.3 deg

I'm out of town right now, but I'd be happy to check the exact spec in the factory manual when I get home. On my CJ the specification is 5 degrees positive. I think if you keep 5 degrees you maintain return to center and should avoid any problems. Obviously the caster you select affects the pinion angle also, so take that into consideration as you are looking at your setup. What exactly are you doing? If you are simply adjusting control arms and the front end will be together sitting on the tires I would be surprised if you could even measure the caster to within 1 degree unless you make a jig that will accurately determine the ball joint position to a flat surface... I measured mine with the knuckles off with the axle sitting on jackstands with all the weight on the springs.

[nagal]

% = degrees, no clue why I was using that. I have the factory spec here somewhere but from what I have read its next to impossible to achieve on a lifted vechicle do to the pinion angel.

What I am trying to achieve is to get my caster as close to spec as possible while maintaining a good pinion angel. I am trying to work out some steering issues that have cropped up since going to a hi-steer with wj knuckles.

I don't expect super accurate measurements doing it in a driveway but need/want to get it set close to reasonable. I figure this is a good time for me to check it because I will be re-adjusting the control arm lengths to pull the axle back. When I first swapped in the D44 set the control arm lengths way to long and now having issues with track bar rubbing against the housing. I know that is an issue period with the RE adjustable track bar and a Rubi D44 but I can minimize it some by get the axle pull back.

If none of this makes sense its because I am 5 minutes from passing out in my bed, sleep isa good thing