Thoughts on cross caster

[Roky]

Yes , currently running falcon adjustable but have also tried MC stabilizer and oem with no change in pull.

We’re narrowing it down, lol, hopefully it’s the tires.

Sponsored

 

[JMONEZ]

We’re narrowing it down, lol, hopefully it’s the tires.

I sure hope so, thanks!!!! Merry Christmas and thanks for your time and suggestions

 

[Roky]

I sure hope so, thanks!!!! Merry Christmas and thanks for your time and suggestions

No problem, let us know how you make out... merry Xmas.

 

[JMONEZ]

No problem, let us know how you make out... merry Xmas.

Will do!

 

[Carlton]

Ive always run higher caster on passenger side to compensate for crown in the road.

Yes, correct. I typed incorrectly.

 

[Arrowhead]

You want more caster on the passenger side, not the driver side. .2 to .4 degrees more is a good split. If you're still having pull issues I'd check your that your rear axle is square to the frame (use a measuring tape from one of the body bolts). If that checks out see if you can mount up another set of wheels/tires to see if those tires are the culprit.

I'm still not understanding how you can set driver and passenger caster different on a live axle. Is there that much flex in the axle assembly that it can be adjusted? Wouldn't that put undo stress on the control arm joints trying to force a caster adjustment left or right?

 

[JMONEZ]

I'm still not understanding how you can set driver and passenger caster different on a live axle. Is there that much flex in the axle assembly that it can be adjusted? Wouldn't that put undo stress on the control arm joints trying to force a caster adjustment left or right?

That’s my concern also, but after having multiple 4wd shops set arms differently and coming up with different cross caster numbers, it must be possible, but how much twist or bind it causes or if it helps, I do t really know. I know I’ve had more caster on pass side before .3 split but still had pull, so.... on to different tires to see it that’ll help first before I change arm length on pass side I guess.

 

[word302]

I'm still not understanding how you can set driver and passenger caster different on a live axle. Is there that much flex in the axle assembly that it can be adjusted? Wouldn't that put undo stress on the control arm joints trying to force a caster adjustment left or right?

We're talking about fractions of a degree. They are likely set up with a small amount of cross caster from the factory.

 

[LittleDog]

My understanding is with a solid axle the cross caster is built in to the axle and you can’t really adjust each side individually to adjust for more or less caster without twisting the axle? That makes sense but I hear of people saying all the time just add more caster to one side, or that when installing lift they put LCAs at different lengths. I’ve been dealing with a pull to the right, my cross caster is just slightly off and everything else seems good but was curious if I could adjust LCA or UCAs on pass side slightly to possibly help increase caster to help get rid of pull to the right without causing joint bind or some other drivability concern with making that adjustment, or if it would even do anything to help. I’ll attach my most recent alignment printout. Also, I guess it could be tires (37” STT pros 28psi) but I’ve tried cross rotating and the pull to The right is still there And didn’t change . America’s tire said they’ll swap out 2 tires to see if it’ll help but believe the alignment is off causing concern. Any ideas, thoughts, or suggestions? TIA and Merry Christmas

Current mods and measurements
LCA- 24 7/16
UCAs-20 1/8
3.5 Mc lift
Mc tie rod
Mc drag link
Teraflex adjustable front UCAs and LCAs
Falcon stabilizer
Yeti track bar

I see that you've had problems with pulling to the right before. Please remember that all of the numbers that you are getting out of your alignment are also dependent on the on the squared-ness of your body, accuracy of holes in the frame, and the sum total of all of the +- tolerances of everything between the frame to where the rubber contacts the ground, not to mention exactly how accurate your shop's alignments actually are.

The numbers also seem large sometimes, but remember that you are talking about 1/10 of one degree out of 360, across 60-whatever inches of axle shaft. Even if it does seem strange that you can add twist to an axle, it is only the outer shaft, and it is held in place by two tons plus of weight and however many ft/lbs of torque they felt like applying that day. If you couldn't twist an axle slightly, you couldn't adjust your adjustable UCAs and LCAs easily anyway. Frankly, I'm surprised that you didn't mention your weird SAI angle differences.

Often times, these numbers cancel themselves out. For example, you can have wacky cross-camber numbers that functionally equal zero if you also have funny (for the rest of us) torsion in your frame. A striking visual example would be a vehicle with extremely offset thrust, combined with (or possibly corrected with) extreme cross-toe. Looks like it's driving diagonal or constantly turning when it's actually tracking perfectly straight. I used to have a dog that walked like that.

In addition, the broad brushstrokes that many people paint on how you should have X amount of caster or Y so much toe often don't take into account how the sum total of your assembly works together, i.e. each of the values, toe, camber, caster, and SAI will affect and multiply the effects of the others. When you add all the variables that determine exactly how your particular Wrangler drives, only you know how your jeep will behave in specific conditions, nobody else, and only you know exactly how it reacts when you change any one of the wheel alignment values.

I'd say that you should use those alignment numbers as a baseline, and adjust accordingly. If the final numbers seem strange, so be it, so long as it works. It might take some trial and error and resetting back to zero a few times, but it seems you have the skills and the gumption to do it. On the plus side, you have 37s, a 3.5" lift, the know-how, and presumably the tools to adjust things; you can drive for a minute and then pull over, crawl under, and change things on the fly if you wanted to.

I've said before that I pulled over into parking lots to adjust my drag link on the fly when I first got my JL, and you seem to have much more wrenching time than me. It took me quite a few adjustments, but after I took into consideration the crown of the road and my normal driving conditions, I've settled on settings that work for me. She probably wouldn't track straight and true if you put my jeep on some magical perfectly flat plane that extended into infinity, with no hands on the wheel, but I certainly consider it a fair compromise for the roads that I generally travel on.


A slight jab at you though, if you have 37s and a 3.5" lift, I wouldn't think that driving straight on pavement was your primary concern.

 

[Arrowhead]

Also, I guess it could be tires (37” STT pros 28psi) but I’ve tried cross rotating and the pull to The right is still there And didn’t change .

There was a thread about the STT pros pulling right:

https://www.jlwranglerforums.com/forum/threads/cooper-stt-pro’s-causing-pull.43403/

Sponsored