Teach me about my Alignment specs post MOPAR 2" lift

[XraytecH]

Got an alignment done post MOPAR 2" Lift and front & rear adjustable track bars installed.

Post Lift Install/Before alignment
- Camber is fixed.
- The Mopar Lift Caster is slightly above spec.
- Toe slightly out.
- Thrust Angle is out of spec.

Post Alignment
- Camber fixed.
- Can't adjust Caster since the MOPAR Lift has fixed length lower control arms.
- Toe is pretty much straight ahead.
- Thrust Angle basically unchanged.

I have two questions...

1 - Should I get shorter control arms to get my Caster within spec or leave as is?

2 - Is Thrust Angle worth chasing?

All that being said, IT'S A JEEP not an F1 car. I felt no difference before and after the alignment.

And yes, I did give the Alignment Shop the factory specs.

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[LostWoods]

Negative toe means the forward edge of the tire is pointed outward and positive means it's pointed inward. Positive left and negative right like you have means your axle is slightly out of square with the vehicle centerline and the right side is likely very slightly forward of the left. The thrust angle is deviation from the centerline or basically half the left toe minus right toe. Those measurements are not that terrible but are pushing the limits of what I'd consider acceptable. Generally you need to be pushing toward a full degree of thrust to have it be noticeable and while I wouldn't buy parts to fix it, I would try to get that closer to zero on my own truck if I already had adjustable arms.

Front caster should be >5 degrees with a lift because it increases stability. Honestly I'd dial in anywhere between 5-7 degrees depending on how bad that throws out the pinion angle.

With solid axle vehicles, the only alignment things that change with a lift are axle centeredness (tends to shift driver side without a longer track bar) and steer-ahead. Total toe (which impacts tire wear) will not change but your wheel will be crooked as the drag link will typically be set too short. When people get alignments after a lift, it's either to properly set adjustable arms and track bars or they're really only fine tuning the drag link to get your wheel straight.

 

[XraytecH]

Negative toe means the forward edge of the tire is pointed outward and positive means it's pointed inward. Positive left and negative right like you have means your axle is slightly out of square with the vehicle centerline and the right side is likely very slightly forward of the left. The thrust angle is deviation from the centerline or basically half the left toe minus right toe. Those measurements are not that terrible but are pushing the limits of what I'd consider acceptable. Generally you need to be pushing toward a full degree of thrust to have it be noticeable and while I wouldn't buy parts to fix it, I would try to get that closer to zero on my own truck if I already had adjustable arms.

Front caster should be >5 degrees with a lift because it increases stability. Honestly I'd dial in anywhere between 5-7 degrees depending on how bad that throws out the pinion angle.

With solid axle vehicles, the only alignment things that change with a lift are axle centeredness (tends to shift driver side without a longer track bar) and steer-ahead. Total toe (which impacts tire wear) will not change but your wheel will be crooked as the drag link will typically be set too short. When people get alignments after a lift, it's either to properly set adjustable arms and track bars or they're really only fine tuning the drag link to get your wheel straight.

Thank you for the insight.

 

[XraytecH]

Negative toe means the forward edge of the tire is pointed outward and positive means it's pointed inward. Positive left and negative right like you have means your axle is slightly out of square with the vehicle centerline and the right side is likely very slightly forward of the left. The thrust angle is deviation from the centerline or basically half the left toe minus right toe. Those measurements are not that terrible but are pushing the limits of what I'd consider acceptable. Generally you need to be pushing toward a full degree of thrust to have it be noticeable and while I wouldn't buy parts to fix it, I would try to get that closer to zero on my own truck if I already had adjustable arms.

Front caster should be >5 degrees with a lift because it increases stability. Honestly I'd dial in anywhere between 5-7 degrees depending on how bad that throws out the pinion angle.

With solid axle vehicles, the only alignment things that change with a lift are axle centeredness (tends to shift driver side without a longer track bar) and steer-ahead. Total toe (which impacts tire wear) will not change but your wheel will be crooked as the drag link will typically be set too short. When people get alignments after a lift, it's either to properly set adjustable arms and track bars or they're really only fine tuning the drag link to get your wheel straight.

Anything I can do to improve the Thrust Angle out side of installing 8 adjustable control arms and front & rear track bar relocation brackets? Would adjusting the axle center via the adjustable track bars help? Or is it just the nature of the beast.

 

[Renegade]

Anything I can do to improve the Thrust Angle out side of installing 8 adjustable control arms and front & rear track bar relocation brackets? Would adjusting the axle center via the adjustable track bars help? Or is it just the nature of the beast.

All they did during your alignment was set the toe and steering center. Everything looks good with the exception of the thrust angle. Have you measured to make sure the rear axle is centered? They typically don't adjust those at alignment shops unless it is a lift installer.

 

[XraytecH]

All they did during your alignment was set the toe and steering center. Everything looks good with the exception of the thrust angle. Have you measured to make sure the rear axle is centered? They typically don't adjust those at alignment shops unless it is a lift installer.

I have an adjustable track bar in the rear and adjusted the center within 1/8 of an inch with the gas tank half full and a 200lb DECKED storage box in the back. I figure trying to get the axles front & rear dead center is like trying to heard cats so 1/8 off is good enough.

 

[LostWoods]

Anything I can do to improve the Thrust Angle out side of installing 8 adjustable control arms and front & rear track bar relocation brackets? Would adjusting the axle center via the adjustable track bars help? Or is it just the nature of the beast.

if you're within 1/8" like you said then that's close enough and adjustable track bars generally replace the need for brackets unless you're getting bumpsteer issues. Your axle will move side to side as the suspension goes down the road (hell you'll get more than 1/8" difference just from static weight back there) so there's no need for perfection.

For adjusting toe/thrust, you'll need at least the 4 rear arms to do that. Control arms hold the axle static and there's just nothing else to adjust.

 

[Renegade]

I have an adjustable track bar in the rear and adjusted the center within 1/8 of an inch with the gas tank half full and a 200lb DECKED storage box in the back. I figure trying to get the axles front & rear dead center is like trying to heard cats so 1/8 off is good enough.

If it drives good, I would let it ride then.

 

[Readyt]

I had mine redone by the dealer after the Mopar lift, but I'm now concerned they set the alignment up for non lifted with smaller tires. Goes down the road straight, but I'm getting some feathering in the tires.

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