Fitting 33" tires with NO CMC and maintaining OEM Specs.

Got my truck fully dialed within all factory Specs. I'm running 285/70R17 Ridge Grapplers on 17x9 Procomp with 4.75" BS. (I only have 2" lift Bilstein 5100 with OME 887 coils.)

Set my SPC UCA's to setting "F" and had my local alignment shop set my Caster to 2.5* and my Caber to approx. 0*. Sat setting "E" @ 1.8* Caster I had very slight rubbing while reversing and turning.
But now that I'm at setting "F" and set to 2.8* Caster there is full clearance of the cab mounts.

Th only thing was that I needed to move the front fender liner forward about 3". But that was easily done with minimal cutting of some plastic.

The good thing is that I could still go to setting "G" and move the tire forward even more to get additional clearance if needed.
These are not my permanent set of wheels and tires. (I'm currently waiting for them to come in).
But just to let people know that it is possible to fit 33" tires without a CMC.

The main reason that most people need to do a CMC is because the aftermarket UCA addd CASTER. Which moves your tire towards the cab mount.

With the SPC UCA you can move the CAMBER to allow the correct Caster.

I'm sorry I should have done a proper write up on this. But I attached some pictures of the amount I needed to trim from the front fender.

 

Good write up

 

That looks like a JBA uca…not spc. And you can’t max out the JBAs because the caster is already built in.

 

Actually those are SPC, I think he got them custom painted. He has another thread that shows them before he installed it

 

They are SPC UCAs painted red. You can take a look at the links in my sig. to see things about lifts and alignment

 

At full lock I have about 1" of clearance from the cab mounts.


Front has about 2" from the front fender liner.

Half turn there is still adequate room for tire articulation.


SPC UCA's.

 

Will they rub off road?

 

They shouldn't because that is measuring the furthest part of the tire. The 33" tires should have full articulation with out rub.

Sorry I for got to post the adjustment sheet:

 

The only problem with having the SPC's set in position F, while still having 2.5°+ of caster is you are pushing the LCA forward, which puts strain on the lower control arm bushings. In my experience, with the arms cranked so far forward, side loading the bushings, they fail every 8-14 months or so with lots of off road abuse. For normal Street driving they should last a few years probably.

 

Should stuff it and see

 

yep!

 

Aren’t you better off gaining caster from the UCA vs the LCA?

 

I respectfully disagree.
Is it any worse than the stress that you steering and LCA's see with high caster? ( like 3*+) I really doubt it.
So called "Pushing the LCA's forward". It's part of the factory setting that the LCA's are designed to do. Toyota designs these to run between 1.3*-2.8* Ideal is 2.0* with stock tires. As you go larger you want a bit more Caster for stability at speed. (You can read more about it in my links located in my sig.)
But I'm open for discussion if you have any solid data to support this stance?
We all know that if you plan to wheel hard that IFS components aren't the way to go.

 

NO! I'm not trying to increase the CASTER. I want to remain in the factory specs. (So as not to cause undue stress on the stock components)
I'm trying to correct the CAMBER issue when you lift your truck.
Setting "G" would put it back to stock orientation in regards to Caster. So I'm still adding .25* Caster with the SPC UCAs.

But the SPC allows me to correct the loss of Camber from the lift.

 

For sure you're right, with heavy wheeling, it all needs to be replaced anyway!

I own a shop that exclusively works on off-road Toyotas, so I see a lot, and have installed/run a lot of setups. There's absolutely nothing wrong with your setup at all. I do find that the truck drives better with 3°+ of caster, but it is all a bit personal preference. I try to aim for 3.5°.

The OEM rubber bushings definitely don't like being run at an angle. The stock adjustments are there to correct frame variations, and are also accounting for camber and caster (with stock uca), but aren't meant to be maxed out. When the bushing is at an angle, it strains the rubber, and they end up wearing out and tearing quicker. I've personally gone through 3 sets of LCA bushings before changing everything to uniballs which don't care what angle they are at. I've seen the same thing with several people I know who drive off road a lot, and end up going through LCA bushings basically as often as inner tie rods, which is ever year or so. I just installed a new toyota rack with two new Toyota inner tie rods in December and have already got a bunch of slop in one of them.

But anyway, that's just what I've seen for people that spend a lot of time driving back roads and have their cams cranked to try and fit bigger tires (usually 35s) without tubbing and relocating the cab mount. Maybe the bushings would go just as fast with a more neutral alignment, but I haven't seen people with 33's and neutral alignments going through LCA bushings near as often. There are a lot of variables at play.

 

100% Agree I've seen rack 'n' pinions give out and start to leak from too high caster (within a year of lift install). I always try and stay within reasonable factory specs as to reduce the chance of failure. That's part of why I chose to only do a 2" lift. (I'm tired of changing CV boots)
But what I'm seeing now is the rear lift is going to be an issue in the near future. The AAL is causing the leaf packs to flex in the shape of a "W". It looks like a set of leaf packs are in my near future.

This is just an option for those people who do not want to cut their frame.

Who knows? If I ever decide to go to 35" tires again, there is no way around the CMC and pinch weld mods. (And it will still rub at full stuff)

Alway good to have other people with different perspectives to ponder if there are other factor I may not have considered. (I'm far from perfect, But I know I can learn everyday!)

You have a Great Night!

 

The UCA doesn’t move the tire toward the cab mount or away only the lower cams do that. The UCA adjusts the angle when the tire compressed upward.

The issue has always been under compression.

Nothing new here proper alignment and wheel backspace can negate the need in some cases but entirely too many variables to matter.

Maybe on old beaters. Many people run the LCA cranked forward without bushing failure. I have 4 years and 40,000 hard offroad miles on my truck with no issues.

 

I think what’s trying to be shared is that the aftermarket uca’s with built in added caster do in fact move the wheel closer to the rear of the wheel well. With the fixed ball joint aftermarket uca’s, the upper ball joint is positioned further back compared to oem thus locating the wheel further back. Yes you get more caster…but lose space between tire and rear of wheel well.

There are so many threads that don’t include this info and that leads to people wondering why they increased their caster to +4 and more using aftermarket uca’s but they still rub the rear of the well or cab mounts.

The SPC uca’s have the ability to adjust the caster and camber via the upper ball joint. The SPC’s have multiple caster settings which you can use to get the wheels located where you need them by either adding or taking away caster. When doing this to get more clearance to the cab mounts, the lca’s are positioned at max caster (wheels moved forward). Then the spc ball joints can be adjusted to get the wheel positioned in an optimal place for less or no rub on the rear of the wheel well. As Toku stated, he used “F” upper ball joint location on his spc’s which adds +.25 caster. He tried using location “E” which is +1 caster and his tire was rubbing. So using the upper ball joint location position “F” which is less caster (+.25), it positioned his wheel more forward and which fixed his tire rub.

Pretty sure this is what Toku is sharing….it does work as I’ve used this exact setup on my last 5th gen 4Runner and my 3rd gen Tacoma.

 

There’s so many variations of “33’s” that people get hung up there to. I run the KENDA’s that are 33x10.50 and with only an inch and half of lift and stock uca’s I don’t get any rub on or off road. My wheels are also 17x8.5 with 4.5 backspace and 0 offset. All these things come into play with tire rub. Personally I think the 10.5 width is ideal for these trucks. Hoping to move up to the 35x10.50 in the future at that point I know I’ll have some work to do to combat rubbing.

 

There’s dozens of threads on this already