Everything you need to know about Upper Control Arms (UCA)

Yeah, it's a common point of confusion. So the KNUCKLE its self isn't taller, the hub mounting surface is just moved down. The reason they don't exist for 4x4 applications is that we have CV joints and axles. With a KNUCKLE lift, the mounting surface is right in front of the lower control arm. This would leave no room for the joint and axle.

The knuckle is held UPRIGHT by the upper and lower control arms. The tie rods also connect to the knuckle, but all that does is give you steering, so I'm not counting that.

If you look at either the CST or MaxTrac knuckles, you'll notice that you can't see the LCA balljoint mount. That's because it's behind the hub (unibearing) mounting surface.

my all caps words are not directed at you, it's a general misnomer in the community.

ALL OF THE ABOVE... it irks me.

 

I appreciate the education, you’re a gentleman and a scholar. Forgive my ignorance, but if the LCA connects directly behind the hub mounting surface, how is any lift achieved? Wouldn’t the LCA have to mount higher on the knuckle compared to the stock spindle? Or is there something else in the equation that’s providing lift?

 

LOL. Thank you. I'm kind of an asshole if you meet me in person, but I'm working on it.

On the stock knuckle, the LCA mounts below the hub mounting surface. The lift knuckle moves the actual wheel closer to the LCA. Perhaps pictures will help.

https://maxtracstore.com/content/MaxTracInstructions/GENERAL/2wdvs4wd-final.pdf

 

Got it, that’s very helpful. Thanks again for answering all my questions, you’re the man. I love this forum — a lot of great people willing to share their knowledge!

 

Saved!

 

I have 6112 2 CB shims dr 1 shim passanger currently resting on spring at full droop looking into UCA do aftermarkets have room for the coil? An adjustment to my alignment correct this?

 

For those who have purchased Camburg upper control arms for the 2nd and 3rd gen Tundras. I know that the ball joints are serviceable. My question is what about the top 2 Bushing where the big long bolt goes thru is that White lithium grease that goes in them also supposed to be serviced or is a one time only grease service?

 

You grease them regularly. There is a grease fitting on the bottom of each of the bushing housings.

 

I have found the ideal setup after trying different settings and arms over the last two years.
I am running 6112 and use a 1/2" shim on the driver side and 1/4" shim on the passenger side. This equals 1" lift at driver and .5" lift on passenger.
This does three things: It levels the driver side lean. It provides more droop. It reduces spring preload.
The 6112 are set to 1.9" so the additional shim lift gets it to 2.9".
Droop from ride height is 3.5" of down travel which is important as it avoids the hard top out feeling which is normally felt from preloaded springs at the 2.5" setting with only 2.5" of down travel. In other words it doesnt top out as hard or as often which means it also keeps the tires on the ground with more traction.
I am running a 2018 CM with 17" Rock Warrior wheels with +50mm or 6.4" BS and 315/70R17's and rear 1" lift shackles with 5100's in the rear. It sits perfectly even at all four corners.
From center of wheel to fender is 18.25 at full bump and 28.25 at full droop that equals 10" of clean travel with no tire rubbing.
For UCA I am running @74Weld billet aluminum arms with Moog ball joints and urethane bushings. I have 6 degrees of caster and near zero camber with cams almost in the middle. I could dial it down to 4 degrees if needed but feel 6 degrees is perfect as it drives straight with less effort and doesnt dart when hitting holes or uneven ground. It drives perfectly on the freeway and off road.
No uniballs or rod ends to wear out or service. The urethane pivot bushing reduce road vibration for a quiet and smooth ride.
I worked with @74Weld to determine the ideal geometry for the arms during prototyping and believe it is as good as it gets. He now has a production run complete so arms are in stock as of today. I do not work for @74Weld, I am just letting people know that there is another high end UCA manufacturer in the game. I can contest that the geometry is as good as it gets.

 

Pics

 

ironman pro forge.

 

What aftermarket bump stops did you go with?

 

I see Elements Upper Control arm isn’t on the list....

I just bought the stage 9 Icons but had to Opt out the icon billet for the Billet Element UCA due to them not being in stock.

Any great reviews on the Element billets?

 

so I'm putting 4 Fox 2.5 on my stock tundra with no lift an no lift in further ! an they say no new uca needed ! so am I good to go!! ???

 

You'll be fine, but you're not going to get the alignment benefits of an aftermarket. You will probably need those alignment capabilities if you're going to push the tire size. Keep in mind that you will not benefit from additional up/down travel.

 

Gravity , u mean even when off-roading. Just back from mojave desert road an death valley plus other places, about 1200 miles on rocks sand ,rivers an bumps an though these would enhance my ride..

 

Are you increasing tire size? What are you looking for?

 

No its stays stock size,except I run e10's now
Looking to smooth out washboard road some

 

It will help to smooth out washboard, but some of the larger whoops and deeper holes will require that you increase your travel numbers. The only way to do that is to extend the shock shaft and that will require either lifting the truck or custom fabrication of shock mounts and relocating anything that's mounted to the inner fender and a ton of fender work. The body of the truck will only move if you've run out of suspension (damping, rate, travel, etc.). Without using the UCA and lifting the truck, you're only hitting damping and rate. You will be limited with travel.

 

Ok thanks.

 

do you need to change break lines when lifting it 1-3 inches ?? over any electric lines?? as u can see " I know nothing "

 

Good question. No need to replace brake lines with extended ones. Just make sure to keep an eye on the brake lines when you disconnect them from their mounting locations and don’t stretch them when removing and installing stuff. Be sure to put the brake lines back in their mounting locations so they’re not dangling or getting caught on anything.

 

My SPC’s are eating ball joints. First set might have been my bad for not greasing them for 20K. 20k was what I got out of them. Second set have been greased every 5K and are developing play at about 6K. Stock lower control arms. Bilstein 6112 at top setting.

 

Do you have pictures of them at ride height, full droop and possibly full bump (almost impossible, but gotta ask)?

 

I’m not familiar with SPCs. Do they use their own ball joints or OEM?

 

Their own, not oem. Colorado company I believe.
Say, you ever install your JBA’s? Mine have been on about 5K, just greased yesterday, so far so good.

 

It's a high angle ball joint with a proprietary adjustable mounting surface for caster/camber adjust.

 

jba just ordered! ordered Fox 2.5 shocks!! got them in 2 weeks ,original time frame 26 weeks yahooooo

 

Sorry for the late reply. Didn’t even see your post til now!

Anyway, no. I haven’t installed them yet. I’ve just been too busy to get to them at the moment. I did watch a few youtube videos on how to install them, though. How was your install? Did you have to remove the battery to get the driver side bolt out? Did you notice any difference in ride?

 

JBAs shipped today! Pretty excited to get them in hand.