Alignment, Caster, Clearance, and Driving Report with Light Racing UCAs

Yes you can do that. I did it for the same reason as you. I pre set my SPC upper arms to the +1.00 degree caster position before bringing it in for an alignment.

 

Ok good, i just don't want to sacrifice lower caster by backing down the caster on the spc's from 2 to 1...

 

I put a 3" front 2" rear lift/level kit on my 2008 Tacoma 4x4 sport and I am getting tire rub on inside rear of tire on tight turns. The minute I installed the front lift you could see the positive camber, tires were pointing up and away big time. Big O did the alignment and showed a correction of 1.1 1.0 camber 1.2 1.9 caster and .03 .02 toe. I did my own alignment check pulling up on plastic grocery bags so it turns easy, then with strings get the truck straight and put lines on the concrete so the protractor could mark 20 deg. on the floor. And my readings show 1.1 1.0 camber 3.4 3.6 caster toe was 1/16 tighter in the front of wheel while measuring the string halfway up the rim. I measure front of rim and back of rim on both sides of truck knowing the string is straight off the back wheels. Why the tire rub and how do I get better numbers? Upper control arms? thanks.

 

My factory caster adjustments are just about maxed out and I get the caster numbers you are looking for, but I am running a 3" lift. Your lift is lower so it should get more caster. I had my alignment tech adjust camber using the UCA.

 

Yes, but this thread says that when you adjust caster form the uca the tire goes back and when you adjust it from the lca it brings the tire forward. I

I was good when i had the higher lift, but now its 3/4 lower and its rubbing. That's why i want to bring the uca caster setting from 2 to 1 and hopefully the tech can still get me 2.5 from the lca's...

 

I see what you are saying. I don't think your tech is trying hard enough. Maybe take it to a different Firestone. I've had enough with them and am willing to pay $90 at a different shop each time to get the alignment how I want it to be.

 

So I read through a great deal of this thread from post #1 and it's confirmed what I thought at Town Fair Tire when receiving my alignment results. I have LR UCA's (currently set at the "C" position (+3) on both sides. Below are my pre and post numbers for camber, caster and toe. The alignment tech told me that he couldn't get the camber on the driver's side any closer to 0 because of the seized cam bolt in the LCA. And I expected it to be seized given Toyota's shitty LCA design (there should have been a recall on this in tandem with the frame issues). When I asked him if he adjusted the position of the UCAs at all, he said yes although I think he lied to my face just to get to his next job.



My question is, couldn't the tech decrease the camber by adjusting the UCA to another position (D or E maybe) without even having to touch the LCA? Does the UCA position have to be identical on each side of the truck or can they be independently adjusted as needed? I feel like the tech's UCA knowledge and effort wasn't completely there to get my numbers at or close to 0, 0, 2.5 - 3. How should I proceed to get ideal alignment numbers without addressing the seized cam bolt in the LCA?

 

I don't know how these guys have paying jobs doing this.

Post a picture of the top of the control arms.

Why did you put them at the +3 position?

 

The CASTER is the only thing that will be changed by moving the dial at the top of the spc's from C to D or E.

CAMBER can be changed at the top of the spc's by loosening the top nut and you will see that the threaded end that comes through the top is in a slot that allows it to move in towards the engine and out towards you. Just have the tech max it out there and fine tune it at the lca's.

 

Not the best pics but here they are. Taking a second look at this setup, the passenger side was re-positioned and camber adjusted to get close to the ideal numbers. The driver's side wasn't touched! I initially put them at the +3 position thinking that it would compensate for the LCA being in the neutral position and unable to be re-positioned. Correct me if I'm wrong but this is an easier fix than I thought...the tech just got lazy on the driver's side with re-positioning the UCA.

The cam bolts in the LCA's are seized. How would the tech be able to fine tune it?

 

They won't beable to. You need to fix those cam bolts. Spray and try to break free or replace them. Usually they are rusted to the lca bushings and they also need replaced. Most likely will need to cut out the seized ones.

 

Issue is when you move the uca dial you must loosen the top bolt and camber is completely off so it will change.

Also you can add/remove caster at both lower and upper control arms. If you move the spc uca forward (negative caster) you lose caster but gain firewall clearance.

My 4runner with the spcs at the full forward position and my lcas maxed for most positive caster I got 1.7* and so much firewall clearance I could run 35s with zero trimming. Before 33s would rub.

Doing this you lose dine caster but gain major firewall clearance. I now fine tune the uca to my liking. Eyeball camber and let alignment shop only fine tune with the lca cams.

Caster at 1.5* or more will drive fine and within toyota spec.

 

Tech's are trained to get you in and out. Good luck.

 

So you're saying that by re-positioning the UCA on the driver's side to the position that it is on the passenger side won't improve the numbers? The LCA positions look exactly the same.

 

Yes it will help take away caster and move tire forward if move the spc arm towards front but you will need to eyeball camber.

If your lcas are seized they can't fine tune.

 

I see. Thanks for the info.

 

I think your major issue is the balljoints were installed the wrong way. I'm not sure what setting that equates to, but it's damn sure not +3 caster. The "SPC" logo(flat side) should be facing the tire to be at the +2(neutral) position.

 

Mine at +2(neutral) position.

 

Yes, this is how mine is set up on the passenger side and it produced great numbers. It frustrates me why the driver side didn't get adjusted this way. I'm going to make this adjustment on the driver side then bring it back this week to get properly aligned.

 

That should help but that camber should be near 0 also. Hopefully they can get it with seized cams.