6112 Caster issues

[Bootleg]

At the significant risk of asking a question that may have been answered I'm going to roll the dice. I have just stalled my 6112/5160 with Icon 2" springs with the 6112s set on the 2" setting (4th circlip) which actually yields 2.5". I decided to stay with stock UCAs knowing I would be at the limit and that I might not be able to get quite into specs with caster. Well the guy that did my alignment said he had the adjustments maxed out and was only able to get 0.3* and 0.4*, respectively. I know that better can be done because it's been well documented that people are getting very close to specs or within specs with the right alignment guy. Regardless, 0.3* is totally garbage. I made it very clear before they started work on the alignment that I expected around 3.5* and that it was totally possible with stock UCAs and some effort.

My question is this. I'm taking it back to get realigned next week (at no charge) by their "top" alignment guy who was on vacation when my rig went through. Can anyone give me any tips or tricks I can give to this guy to get me closer to specs? I would assume this guy knows what he's doing and should need a nudge in the right direction but you never know.

 

[Engineer]

I hope you were polite about it, your post reads a little dickish about you knowing what they can get out of your set up. I agree with you that your current number seem low however I do not think you will get 3.5. I have aftermarket UCA and only got 3.5 lass time I went in. Do i think they can do a bit better, sure but it drives fine. Every truck is differant so you really have to be careful about comparing , it's only a ball park.

As far as alignment goes I'll let others chime on that but there is a good thread that someone called out the theoretical adjustments to max out caster. IIRC it making the rear bolt max "positive" fronts max negative but then you will have to adjust back to get camber in spec and that the process should be repeated several times to max caster while keeping camber in spec. fwiw I was able to get caster to 5.8 but then camber was off.

 

[Bootleg]

I hope you were polite about it, your post reads a little dickish about you knowing what they can get out of your set up. I agree with you that your current number seem low however I do not think you will get 3.5. I have aftermarket UCA and only got 3.5 lass time I went in. Do i think they can do a bit better, sure but it drives fine. Every truck is differant so you really have to be careful about comparing , it's only a ball park.

My cousin was actually the guy that did the install so I did everything I could to make sure things stay happy for him at his job. Besides, it never pays to be a dick to the people who are trying to help you. FWIW the guy doing the alignment was not my cousin.

I know there's a very good chance that I won't get back within spec. I do think a lot better can be done and I don't think it unrealistic to get me closer. I would have just hoped that while he was doing the alignment it would have thrown up a red flag if he was 3* off. Again, it wouldn't be unprecedented to get within spec at 2.5" with stock UCAs. That's precisely the reason I stopped at the 4th groove.

As far as alignment goes I'll let others chime on that but there is a good thread that someone called out the theoretical adjustments to max out caster. IIRC it making the rear bolt max "positive" fronts max negative but then you will have to adjust back to get camber in spec and that the process should be repeated several times to max caster while keeping camber in spec. fwiw I was able to get caster to 5.8 but then camber was off.

Thanks for this!

 

[mrevilandy]

I have 6112 set at max as well with my stock uca 2.5 range was max they could get it without going crazy with toe. Aftermarket uca I'm around 4 with almost neutral toe. FYI I had them put about +.5 caster on driver side and it doesn't steer to the right now lol

 

[RonJR]

OP, are you saying that your lift is 2.5" total, or 2.5" from the shocks and another 2" from the Icon spring, for a total of 4.5".

Just based on geometry of the various elements of the front suspension, caster decreases about .8 deg for every inch of lift. So, a 2.5" lift will cost you about 2 deg of caster, whereas a 4.5 inch lift would decrease caster by about 3.5 deg. Depending on where you started, your alignment guy could actually be right.

 

[eblamble3]

OP, are you saying that your lift is 2.5" total, or 2.5" from the shocks and another 2" from the Icon spring, for a total of 4.5".

Just based on geometry of the various elements of the front suspension, caster decreases about .8 deg for every inch of lift. So, a 2.5" lift will cost you about 2 deg of caster, whereas a 4.5 inch lift would decrease caster by about 3.5 deg. Depending on where you started, your alignment guy could actually be right.

2" Icon spring would be the rear lift.

 

[Bootleg]

2" Icon spring would be the rear lift.

Correct.
2.5"+/- of actual lift in the front and 2" in the rear.

 

[eblamble3]

Correct.
2.5"+/- of actual lift in the front and 2" in the rear.

FWIW I have the 6112s on mine set one notch below yours and truck drives fine. I don't have the specs on the alignment anymore though so not sure what everything is at.

 

[Bootleg]

FWIW I have the 6112s on mine set one notch below yours and truck drives fine. I don't have the specs on the alignment anymore though so not sure what everything is at.

Mine drives more or less fine with the caster out of spec but the toe and camber are both well within range. My concern is the nervous handling at highway speeds (55mph +). It takes very little steering input to make pretty big movements, which I'm sure I can get used to. I'm worried about when something happens in front of me and I have to react and a possible over correct. Specs are 3*+ for a reason and highway stability is a big deal to me. I could live with it but I'd rather not roll the dice if it can be corrected.

 

[RonJR]

I don't like nervous handling, either. Mine is at about 2.5 deg (with frozen cam bolts, so not adjustable until I do some major work), and even at that it wanders more than I like, especially on interstates that are rutted by all the heavy trucks. If it was me and the alignment shop couldn't get it any better, I think I'd spring for new UCA's to get it in spec.

 

[Runn4est]

Don't have your shocks, but I do have 2.5 inch spacers, and the alignment shop spent almost 2hrs on my alignment to get JUST under spec of 2.5. It feels just fine at highway speeds, so I'm not too worried. When we move from spacers to a real lift, UCAs will probably be going on at the same time.

 

[NinjaOne]

Something to remember is the rear lift impacts caster as well.

2.5"/2" lift retains more of the factory rake than most leveling lifts. This reduces caster, are you sure the guys with more caster are running the same front/rear lift size? IIRC, extra half inch in the rear over the regular 2.5"/1.5" will reduce caster about ~0.5°

You're prob. right in that you can get more, but I would expect closer to ~1.5-2.5° max. while still keeping everything else in aligned right (low side is more likely)

 

[Bootleg]

You're prob. right in that you can get more, but I would expect closer to ~1.5-2.5° max. while still keeping everything else in aligned right (low side is more likely)

I'd be a lot happier with 1.5*-2.5* than I am 0.3*, no doubt about it.

 

[NinjaOne]

I'd be a lot happier with 1.5*-2.5* than I am 0.3*, no doubt about it.

For sure.

I'm at 1.8° on my 4th gen with a 2.5/1.5" lift and stock UCA. I'm sure I could do slightly better if I were to be persistent with the alignment tech. Prob. not more than 2.2° for me. Eventually I'll put aftermarket UCAs on.

 

[Jhalko]

Mine drives more or less fine with the caster out of spec but the toe and camber are both well within range. My concern is the nervous handling at highway speeds (55mph +). It takes very little steering input to make pretty big movements, which I'm sure I can get used to. I'm worried about when something happens in front of me and I have to react and a possible over correct. Specs are 3*+ for a reason and highway stability is a big deal to me. I could live with it but I'd rather not roll the dice if it can be corrected.

When I lifted 2.5" up front with stock UCA's I was on the line for spec on caster, it drove fine but was twitchy on the highway. That is normal as the stock UCA's can only go so much. You can have another alignment but what you describe seems normal, aftermarket UCA's can get you the higher caster and drive you seek. FWIW I drove mine like that for a year before slapping on the new UCA's.

Post your alignment sheet.

 

[Bootleg]

When I lifted 2.5" up front with stock UCA's I was on the line for spec on caster, it drove fine but was twitchy on the highway. That is normal as the stock UCA's can only go so much. You can have another alignment but what you describe seems normal, aftermarket UCA's can get you the higher caster and drive you seek. FWIW I drove mine like that for a year before slapping on the new UCA's.

Post your alignment sheet.

Hopefully they can get it closer. It does drive twitchy which is really the only thing that concerns me. If I can get around 2.5* I'll be much happier.



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[Bootleg]

Second attempt was no better. He did, however, get everything else a bit tighter and added a slight bit of toe-in which helped the nervous behavior at high speeds.

I'll be taking it to another guy who specializes in lifted 4Runners and FJs soon. I should have taken it there to start but I figured I'd let the shop doing the install handle the alignment as well.

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[eblamble3]

Second attempt was no better. He did, however, get everything else a bit tighter and added a slight bit of toe-in which helped the nervous behavior at high speeds.

I'll be taking it to another guy who specializes in lifted 4Runners and FJs soon. I should have taken it there to start but I figured I'd let the shop doing the install handle the alignment as well.

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Any updates? I just had mine checked since I had installed the SAW coils in back since last time. Here is where I am at on the third notch (2"). Right on the line for caster.

 

[Bootleg]

Any updates? I just had mine checked since I had installed the SAW coils in back since last time. Here is where I am at on the third notch (2"). Right on the line for caster.

None yet. I'm going to take it to the guy who does all the alignments for the local 4Rn and FJ guys locally. Should have taken it to him to begin with but sometimes you have to learn the hard way. He says he can do better so we'll see. I'll post updates once I have them.