4H Pull

Correct.

 

Had my alignment on 23 May 13:

Current measurements:

Left front:
Camber .3
Caster .8
Toe .05

Right front:
Camber .3
Caster .3
Toe .04

Front total toe .09
Front steer ahead 0.0

Left rear:
Camber -.6
Toe .31

Right rear:
Camber 0.0
Toe -.34

Rear total toe -.03
Rear thrust angle .32

 

Aight...so long story short: I get a solid 4WD light (no flashy flashy), I can feel confident that EVERYTHING engaged as planned.

 

Yes sir. as far as i know, never had a false alarm yet

 

I appreciate all the feedback, and hopefully someone else besides me learned something.

Ask my wife, I'm bad (OCDish) about resolving small squeaks, electrical shorts, etc. If something doesn't operate as intended, I have to know why and nip it in the bud. However, this was slightly beyond me. I'm not too familiar with the ADD, obviously, but feel much better about it considering the feedback provided. With all the monitors, sensors, and electrical tolerances, it's highly likely I'd get some sort of fault indication if something wasn't working as it should, especially within the 4WD system. The geometry issue brought on by the lift will just be something I have to deal with, unless a future alignment resolves the issue.

 

Your Caster is terrible, you want ~2.5, and 3 is ideal. I bet the .3 on the right is not helping the pull, if not causing it all together, but I may be wrong. New UCAs wil get you to 2.5 or higher in caster.

 

So, what part do you think may be causing the pull...how low the casters are or the difference in the L and R?

 

I am no expert on alignment, never learned it

doording and goufcustom both will hopefully fix me if i say somehting wrong here,

but i would think the low caster is what makes it amplified, and the difference in the casters from side to side is what makes it "favor" one side

Im pretty mechanically smart, but i may be using the wrong terms here since im not an alignment guy.. Just trying to make sense and help make sense

 

^ but ive driven some way bad and never had much issue. (at least the same as you describe)

i bent the front axel on a 52k pound truck, a long way, and the tie rod as well (4-6 inches of toe) now that was a truck that had bad alignment and pulled

 

oh ok, you two just sounded more knowledgeable

So your in the same boat as me

 

Needs more cowbell.
...I mean caster.

 

LOL!

 

Mine is at 2.8 degrees and very stable. Low caster makes the truck "wander" and maybe being half a degree off from each other could possibly make it amplify the torque steer as DoorDing and others have said.

 

New UCAs aren't in the budget just yet, but I did find this, FWIW:

"Cross caster difference from right side to left side will cause a pull to the side with the least positive caster."

https://www.uvu.edu/auto/pages/lessons/caster_angle.html

Totally supports what DoorDing and others have said. Funny thing is - the thing drives like a champ in 2WD, straight as an arrow...and no 'wobble.' Of course, I've only had her up to ~75-80 mph. Dynamics do change when you've got 4 wheels pulling, vice 2. I'm heading to a reputable alignment shop this AM to discuss the issue and see what they can do about equalizing the L and R caster. I'd assume the caster is maxed, but we'll see soon.

 

Right, even if its maxed, and if it was super screwed up. they should at least find the happy medium that matches.. Well a little different as far as i understand because the way the roads are designed to lean for watershed.. but, purely on guesswork, it just looks odd to have such different numbers i guess. who knows, i am cert. loopy.

 

If caster delta does create pull to the side with the lower value, you'd think the L caster value would be slightly lower to compensate for road crown. My L is .5 deg higher.

 

it must be my over tired brain from being up all night, i remembered a way off number.

I dont think .5 degrees is or would be that dramatic.

Im curious what the pros say!!

 

L is .8 and R is .3. I'm curious as well!

Up all night? What do you do?