Caster/alignment issues

[NW-ZJ-SCOTT]

this is on a zj.. but everything i am dealing with is identical to an XJ..
6" lift RC CA drop brackets.. adjustable track bar.. fixed Aftermarket CA's..



Took my rig to les schwab for an alignment (west coast tire chain) before the alignment my caster was decent, But now after the alignment my caster is visually TERRIBLE.. the outer edges of my tires are hardly even touching the road surface.

The alignment tech told me that it has to be that way because its lifted so high.

my Balljoints are brand new, i really dont want to replace them with adjustable's..


Right now the lower control arms are pushed all the way out (Drop brackets have 1.25" of adjust-ability for the lowers) This thing wonders TERRIBLY now.. almost white knuckle. The wheels are straight and the the steering wheel is straight (for the most part) but the caster just seems extreme IMO!

At this point i am within their warranty period.. so i am going to demand they make it right.. but i wont take it back to the same guy!
Pic

 

[RCP Phx]

Caster and what looks like camber are related to each other along with toe-in,need real numbers to validate anything! In the mean time relax,Ive seen this many a time.

 

[whitexj98]

Well caster is the tilt of the knuckle front to back, camber is the outer tilt of the tire. Camber shouldn't be adjustable, the caster on a xj is somthing like 7 or 8 negative. So I don't understand exatley what the tech did because you would want as much caster untill you start to have drive shaft vibes. If the lowers are farther out then you should have more negative caster, more negative caster will give cause the steering to wonder less. Did you get a print out? If so post the results.

 

[Tally_XJ]

Positive caster is more stable steering, not negative caster. Pushing the lower CA's out longer gives more positive caster.

 

[whitexj98]

Positive caster is more stable steering, not negative caster. Pushing the lower CA's out longer gives more positive caster.

You sir are correct, my bad.:roll:

 

[WB9YZU]

Yup, OP is confused about Caster and Camber.

The alignment Tech probably adjusted the CASTER to what would be factory: He pointed the pinion at the Xfercase and probably didn't even look at the Caster numbers before he did it. That is how the FSM calls for it. Unfortunately, 6.5" lift ain't stock.

That would rotate the axle quite a bit from the stock angles and strongly affect CAMBER, which is the adjustment you see causing the titled in wheels.

To get the CAMBER Close, the CASTER numbers will have to be close to stock. This means that the Pinion Angle will be Off, probably 4deg Pinion down. If that doesn't cause the front DS to vibe, go with it. Otherwise a number of folks make leamon aid at this point and deal with both a reasonably bad Pinion Angle AND reasonably Bad Caster (and Camber) angle.

And yes, this should be in OTHER tech.

 

[lyleorszulak807]

yeah I lost all faith in alignment shops when the last one I went to for DW issues told me it was because I was missing my front sway bar. Asked for my money back and got the hell out of there. Now I just do everything my self and it rides like a cadi...

 

[Dewidge]

Had that same result from Sears... Was told not having my sway bar hooked up was causing my wobble.. I laughed and asked if he knew what a sway bar was.

Turned out to be a lower control arm mount that was breaking off.

 

[ericfx1984]

actually I think if the pinion gets pointing up enough it could change the caster

for instance if you rotated the pinion upward 90 degrees... basically making the diff cover face the ground... and then you adjusted the toe in, it would actually be moving the top of the tire in and out...

that is what happened here... not to the same extreme... but still

 

[Tally_XJ]

actually I think if the pinion gets pointing up enough it could change the caster

for instance if you rotated the pinion upward 90 degrees... basically making the diff cover face the ground... and then you adjusted the toe in, it would actually be moving the top of the tire in and out...

that is what happened here... not to the same extreme... but still

You would never get the front rotated that far. The steering rods would clash before that happened and the pinion angle would break the yoke.

 

[ericfx1984]

You would never get the front rotated that far. The steering rods would clash before that happened and the pinion angle would break the yoke.

I know that you could never get it rotated that far... it was just an observation :laugh3:

 

[1SYCRYD]

You have a camber isssue not caster... Install adjustable upper ball joints from MOOG and then have the camber corrected.. Also check your hub bearings for excessive play..

Camber is a tire wearing adjustment, Caster is not tire wearing but will cause high speed instability and weak return to center steering..

http://www.moog-suspension-parts.com/proddetail.asp?prod=MOOG%2DK7403

 

[dellstopjeep]

the problem with castor at taller lift heights is it tends to create a lot of driveline vibes when its dialed into spec. I have locking hubs so this isnt a issue but before this at six inches of lift I wandered alot, then dialed my rig in properly but had to then adjust back about a degree to eliminate driveline vibes.

 

[GrimmJeeper]

I just went through this and my XJ is 3-4" higher than your ZJ up front. I was still on stock uppers and fixed lowers for a 4" lift, and it drove OK.. wandered a bit but not scary. I replaced the uppers with longer fixed arms and the camber turned in at the top an insane amount and it was next to impossible to control on the street.

with drop brackets your arms need to be pretty close to stock on 4-6" of lift. any longer and either the track bar gets pushed out of it's operating angle or your pinion end up pointing at the sky causing the problem you are having right now with camber. sounds like you need shorter uppers then you can use the adjustment on the bracket side lowers to fix your caster angle and get it driving nice again.

 

[jeeperjohn]

The only way to get proper castor with that much lift is to rotate the inner "c"s. Anything else is going to be a compromise that will give you poor performance in some way.

 

[NW-ZJ-SCOTT]

they are stock uppers, is there even an adjustable that goes shorter then that?

 

[RCP Phx]

Measure your caster and take a pic of your pinion angle!

 

[jeepboy381]

You can do an alignment very easily yourself, only things you can adjust on an XJ are caster, toe, and steering wheel centering. You want as much negative caster as you can have without your driveline vibes getting to bad. You want your toe at 1/8" toe in. It looks like your Jeep is toed out really bad which is making the camber look off even though it is not adjustable.

 

[NW-ZJ-SCOTT]

 

[RCP Phx]

Get some adj uppers a dial it in,call it DONE!