Alignment Help

[LoJac963]

I was hoping to get some help from everybody, I have a annoying pull to the right.

I have a 2020 Gladiator Rubicon with the Mopar 2-inch lift and a Teraflex 1.5 inch level kit. I have also had the TSB for the steering box already performed. I also have an adjustable track bar with the front axle centered.

It seems the pull to the right began after the Teraflex level install. Recently I added Teraflex adjustable lower control arms and set them at 24 inches and 7/16 per their instructions for a single set of arms at 3.5 inches of lift.

When I installed the control arms I actually lengthened the passenger side one turn longer thinking it would push the axle forward and take away the pull to the right but that did not fix it. What's interesting is the specs on the alignment saying that the Caster angles the same on both sides when the passenger side LCA is longer.

This is my first Jeep so I'm new to the suspension geometry but I don't know if I need adjustable upper control arms so I can push the passenger side axle forward to take the pull to the right out?

So far recommendations I have is to:
--install a rear adjustable track bar to fix the Thrust Angle
--check brakes to see if any on the right are sticking
--make front LCAs longer
--swap wheels (already swapped the front)
--put stock steering stabilizer back on since non-adjustable Fox can push (mine does not push or pull when taken off)

Sorry for the long post and thanks everybody for the help in advance.

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[ShadowsPapa]

You can't change caster difference by changing one of the control arms!
In short, you can't twist a solid steel tube so that the bottom of one end is further forward than the bottom of the other.
Two things are set at the factory and there isn't a bloody damn thing you can do about it -
CASTER DIFFERENCE (because you can't TWIST a solid steel tube and have one end different)
CAMBER - unless you use some fancy bushing or ball joint that can be turned to change things - stock parts you can't possibly change camber.

ALL YOU CAN DO is change caster by the exact same amount on both sides. In other words - if one is .25 more positive than the other side, changing control arms may get you more caster -but that one side will STILL be .25 more positive.
Caster OFFSET or DIFFERENCE between left and right is welded in to the axle. You can't twist it.

What you CAN change is toe, steering wheel centering and total caster - you'd increase it the exact same on each side.

You said you tried a TIRE ROTATION - Pull is very often caused by the TIRE.
Ideally if a vehicle pulls to the right, you'd simply switch the front tires, put the right on the left and the left on the right - and make sure the inflation is exactly the same to the pound on those tires.
Caster would have to be quite different left to right to cause a pull.

A positive thrust angle will try to steer the vehicle to the left, while a negative thrust angle will try to steer the vehicle to the right. So that's definitely a good area to check if the caster is in specs and the tire swap has been done.

 

[LoJac963]

A positive thrust angle will try to steer the vehicle to the left, while a negative thrust angle will try to steer the vehicle to the right. So that's definitely a good area to check if the caster is in specs and the tire swap has been done.

Your post makes sense. I found it odd how the passenger front LCA being a turn longer yet is basically the same caster on alignment specs. Some have said the frame mounts aren't exact so don't get too hung up on that.

Thrust angle, mine being 0.16 degrees, would that cause a pull to the passenger side? I do not have an adjustable rear track bar and some have said that would be the first step, recenter the rear axle as I did with the front.

Thanks for your help!

 

[LostWoods]

You can't change caster difference by changing one of the control arms!
In short, you can't twist a solid steel tube so that the bottom of one end is further forward than the bottom of the other.
Two things are set at the factory and there isn't a bloody damn thing you can do about it -
CASTER DIFFERENCE (because you can't TWIST a solid steel tube and have one end different)
CAMBER - unless you use some fancy bushing or ball joint that can be turned to change things - stock parts you can't possibly change camber.

You absolutely can change caster on just one side. SInce the axle isn't fixed in space, adjusting any of the four contact points (i.e. arms) will rotate and shift the axle. So clearly, any adjustment to one side will impact the other as well and it's not good to do this outside small adjustments (otherwise you can see weird binding) but it is possible to do with adjustable arms.

@LoJac963 From an alignment sheet perspective this looks good. The only worry I'd have is that the cross caster being neutral might induce a pull right on crowned roads. If it does it on flat roads (e.g. middle/left lane of the freeway) then you likely have other issues. A few thoughts...

• Your rear thrust angle is insignificant but you might have an axle centering issue that the alignment won't detect.
• Tires are a potential culprit as was said but if you swap fronts and the pull doesn't swap with it, it's not that.
• Fox stabilizers do tend to pull right but if you disconnect it as you said you have, that eliminates that.
• Brake drag is uncommon on new vehicles but you'll know that very quickly after an hour drive because the wheel will be blistering hot.
• LCAs will have minimal impact on caster because of mounting location. The lower is generally for correcting wheelbase (as lifting pulls the tire rearward a small amount) while the upper being mounted far from the axle itself allows for greater caster adjustment.
• Manufacturing is somewhat precise but not that precise and if you take 10 vehicles off the production line, all 10 will have different alignment readouts. There's wiggle room in every mounting interface so having slight deviations is normal and why the spec range is wide.

My recommendation is to double-check that your springs and spacers are aligned and seated properly. I have the Teraflex and I know after my install I had to finagle them into place to seat the little nubs properly. If your left side isn't seated correctly, you will have slightly more lift on that side which would push the truck right and wouldn't change the alignment. Otherwise this is one of those can of worms scenarios because you're mixing a lift spring and a spacer where just a taller lift spring would be a better solution.

 

[LoJac963]

My recommendation is to double-check that your springs and spacers are aligned and seated properly. I have the Teraflex and I know after my install I had to finagle them into place to seat the little nubs properly. If your left side isn't seated correctly, you will have slightly more lift on that side which would push the truck right and wouldn't change the alignment. Otherwise this is one of those can of worms scenarios because you're mixing a lift spring and a spacer where just a taller lift spring would be a better solution.

Thank you, appreciate the input. I will double check the install but pretty sure they were correct but double checking can't hurt. Honestly I have thought about ditching this whole damn setup and doing with a Metalcloak or similar 3.5" lift. This is insanely frustrating because there are many people running my exact setup without adjustable front LCAs, track bars etc without issue. Really pisses me off and I really don't want to keep throwing parts at it.

You don't think a rear adjustable track bar to improve the thrust angle will help at all? My rears only have the 2" of lift from the Mopar kit and the axle didn't seem to shift much.

 

[ShadowsPapa]

So how can you rotate one end of the axle housing and not the other?
Have you taken a steel pipe and tried moving the bottom of one end forward without changing the other end at all?
You can shove the whole thing forward on one end but you then have a truck that isn't going to track straight. You've put it into a bad situation.
That tube is solid - if you rotate one end, which is what you do with caster on a solid axle vehicle, you rotate the other end. But if you hold one end, best you can do is shove the whole end forward and then you are really screwed up as one end of the tube will be ahead of the other.
You can't gain enough caster to make a difference without shoving that end of the axle forward - leading to one end of the axle being ahead of the other - that's bad.
If he's got one lower arm longer than the other, then that end of the axle will be pushed forward as the other end will hold it from twisting.

 

[kevman65]

Take the leveling pucks back out and see if your problem goes away.

When you pull the pucks, label them as to which side they were on.

Then if your problem has gone away, do a thorough inspection of the pucks and look for deformities and/or a failure. Some of these plastic pucks have been bad from the get go and caused handling problems.

 

[Jeeperjamie]

I'd be inclined to say you got something off with your install of the leveling kit. I got about the same amount of lift as you do with my 2.5" ReadyLift and Rubicon front springs and I still have my stock Trackbar and control arms installed and I do not have any pull at all. I will say most who have installed the Mopar 2" lift say they have a pull to the right, not sure why but there are a couple threads on here about it.

 

[LoJac963]

Take the leveling pucks back out and see if your problem goes away.

When you pull the pucks, label them as to which side they were on.

Then if your problem has gone away, do a thorough inspection of the pucks and look for deformities and/or a failure. Some of these plastic pucks have been bad from the get go and caused handling problems.

That's what I was trying to avoid. I can't tell you how many times I have loosened the front end to install and remove things and reinstall. Damnit but you're right. Technically all the front control arms should be loosened as well right?

 

[kevman65]

Take things one step at a time.

Remove the pucks first. If I read correctly, you adjusted one LCA out farther than the other. I would return that so it matches the other. LCA adjustments should be made with tires on ground and full weight on them. Same for track bar.

 

[LoJac963]

Take things one step at a time.

Remove the pucks first. If I read correctly, you adjusted one LCA out farther than the other. I would return that so it matches the other. LCA adjustments should be made with tires on ground and full weight on them. Same for track bar.

Removed the Fox steering stab, maybe a slight improvement but still pulling right (passenger)

Removed the Teraflex 1.5" level kit, both sides looked fine, they were all installed correctly. No change, still the right pull.

 

[LostWoods]

So how can you rotate one end of the axle housing and not the other?

I'm fully aware it doesn't make sense when you think of how the system should work but I've done it before to appease stubborn old Jeepers who clearly knew more than the collective 60+ years' experience of the other three people standing in the bay. Again, very small adjustments possible and nothign that would make a significant difference but they've shown on the machine and have appeared in subsequent measurments.

So either I'm wrong and our equipment was wrong or this is just one of those weird things that happens because the design is an imperfect system.

 

[LostWoods]

Your post makes sense. I found it odd how the passenger front LCA being a turn longer yet is basically the same caster on alignment specs. Some have said the frame mounts aren't exact so don't get too hung up on that.

Thrust angle, mine being 0.16 degrees, would that cause a pull to the passenger side? I do not have an adjustable rear track bar and some have said that would be the first step, recenter the rear axle as I did with the front.

Thanks for your help!

Thrust angle is a function of toe, not lateral axle position so as long as it tracks relatively straight (i.e. is still perpendicular to the centerline) it's not a problem - thrust angle typically needs to be .5 to a full degree before you really start seeing noticeable pull.

It's possible that an offset axle can cause a pull but I doubt you're getting enough offset from a 2" lift to cause it.

 

[Nespeezy]

I second that motion. Combining the 2 kits may be a factor. Your caster looks a bit high. My recommendation is to bring the caster to 6 degrees. Track bars to center your axles too.

 

[LoJac963]

Removed the Fox steering stab, maybe a slight improvement but still pulling right (passenger)

Removed the Teraflex 1.5" level kit, both sides looked fine, they were all installed correctly. No change, still the right pull.

I also just pulled the Teraflex adjustable LCAs on the front and put the extended Mopar ones with no change. The extended Mopar LCAs are 24 1/4" and I had the Teraflex LCAs set to 24 7/16 per their instructions. I have no idea how many degrees that would take out but the pull is still there.

Now I am back to just a Mopar lift with an adjustable front track bar which was set for the 3.5" of total lift

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