January 10, 2024

Upper Control Arms and 4runner lift

I have a 2023 4runner (Off road premium) that I bought new in September, 2023. In February of 2024 (2/14/2024) I had lift work done by Trail Boss offroad in Tucson. The job did not include new upper control arms. It did include:
Bilstein 6112 front kit
1 inch lifted rear coil springs
Bilstein 5100 rear
The front was lifted 2.5 inches to level the vehicle (the Bilstein kit is adjustable and allows 0.7 to 3.0 inches). Cost was $2500

Shortly after getting the lift done I purchased bigger tires (KO2 in 285 rather than 265), replacing the stock tires, which I gave to my son for his Tacoma.

Andrew is checking into places to get a lift done for his 4runner. He has been advised against both Trail Boss and Desert Rat. The recommended place these days (July, 2026) is Desert Offroad Solutions in Vail. Call Nick at 520-323-7022. He has recommended OME (Old Man Emu) parts for Andrew, which are well regarded.

New information

I am now learning that a front lift over 2.0 inches should include new upper control arms. When I had the work done in 2024, I was told that 3.0 inches was the magic number. It is now July of 2026, so I have been driving this setup for 1.5 years. I have seen no evidence of abnormal tire wear.

One chart is as follows:

0-2 inch lift -- factory UCA are fine
2-3 inch lift -- aftermarket UCA recommended
3+ inch lift  -- aftermarket UCA required

What I have noticed is a noise when I drive into holes or down certain steep driveways and hit the gutter. The jury is still out as to whether this is related to the lift, but I suspect that some limit stop is engaging. I don't know if a new UCA setup will fix this.

A visit to Trail Boss in July, 2026 gave me a quote of $1700 to install SPC upper control arms.

Aftermarket UCA

The "do you need" video is good -- he says the main reason to get UCA is to avoid tire wear issues, but you will also get greater articulation. Claims for an aftermarket UCA:
Improve Alignment -- yes, and important if you lift
Larger Tires -- maybe, but can make things worse!
More travel -- probably not
Stronger -- any UCA is adequate, the LCA takes the big load.
Lift affects both camber and caster (and requires re-alignment). Tinkerer cites the 2 inch rule of thumb. The SPC has adjustable caster and can be very handy to adjust tire fit issues. On the other hand if you buy a UCA that is set up "just right" for your 2.5 inch lift this is a moot point.

Concern about bigger tires is usually by people who want to run 33 or 35 tires.

As far as travel, up is limited by the bump stop and down is limited by the length of the shock. The UCA has no effect on either of these limits. Note that the SPC mounts the ball joint at 90 degrees which cancels the benefit of their high articulation ball joint.

UCA issues with bigger tires

As mentioned above, questions about bigger tires are usually in relation to 33 or 35 tires. I now run 285 tires in lieu of the stock 265. These are more or less 31 inch tires. Different makes of tires have different size and shape. Also "285" is only part of the story. Mine are 285/70 R17 tires.

What I have read so far indicates that I won't have problems. I run the stock TRD rims. If I had spacers or rims with offset, the story might be different. When I install aftermarket UCA in lieu of my stock UCA, I may need to adjust caster to undo the adjustment made when the lift was done with stock UCAs.

SPC versus JBA

These are popular and well regarded candidates to use as new control arms. The SPC allows the ball joint position to be adjusted and is thus well suited for more extreme lift that the 2.5 inches I have. I read that the JBA is "just right" for my 2.5 inch lift and is more robust and durable.

Here are the links to the JBA upper control arms. You need to choose STD or HD. The STD are $603, they are 4runner specific for 1 to 3.5 inches of lift. The HD are $853, and are for Tacoma, 4runner, etc. for 1 to 3.5 inches of lift.

Do I want STD or HD? As Tinkerer says in the video above, the strength of the control arms is not really an issue. Comments I read suggest that HD are overkill unless you are racing or rock crawling. In fact the thicker tubing used on the HD arms may contacts the springs when the STD would not. JBA says the geometry is the same and they are welded on the same jigs.

Here is a video all about mistakes you can make: Skip to 22 minutes in the "common mistakes" video for the "which is right for you" section. SPC is an alignment company, not an offroad company.

The "moving on" video is clearly talking about SPC, though he avoids naming them as such. He went with the JBA heavy duty instead. His SPC bushings are not greasable! The JBA on the other hand have easy greasable bushings (easy, in that you don't need to loosen the through bolt when you grease them). The newest SPC doesn't even have a grease fitting on the ball joint, they are claiming that the new ball joint is "service free".

Note that stock Toyota UCA have no grease fittings, not even on the ball joint.

Some comments on greasing the SPC:

Don’t bother, those ball joints are gonna fail regardless.
I’ve wasted a lot of time and money on SPC and hoping to help others avoid that.
I went through 2 sets of the previous ball joints in 40k miles and SPC said that was normal.

SPC is the most popular, due to adjustability. Icon uses a unique uniball design. JBA offers both a standard duty and a heavy duty. JBA uses their own proprietary ball joint, which is easy to replace. The SPC is a "light duty" UCA given its adjustability. SPC and standar JBA are "entry level" as far as ruggedness. Total Chaos is racing oriented (rock crawling) and insanely strong. Likewise Camburg. Dobinson makes a billet aluminum UCA to save weight, as well as a plain tubular UCA.

DIY install

The claim is that this is straightforward, taking 1-3 hours.
Remove the front wheels.
Disconnect factory ball joint
Unbolt long UCA bolt from engine bay
Grease new JBA bushings
The Skuch video is for the process, and is pretty good. The price on the Skuch UCA set is an amazing $140 for the pair! He recommends a 19 and 12mm gear wrench. He has one short segment that is worth its weight in gold where he lays the new UCA on top of the original UCA and shows how the ball joint location has been relocated to change the geometry! He torques the castle nut between 45-60 -- to get the cotter pin holes lined up (the JBA uses a nylock bolt).

The advice to check torque after 500 miles gets me thinking. What would happen if a shop did this work? Would they have you bring the vehicle in after 500 miles. I doubt it very much.

The Gen 3 video is really good, even though it is an older version of the 4runner.
This is essentially the same as my Gen 1 Tacoma.
They use a puller on the ball joint, which looks great if I can fit mine on my Gen 5.
They torque the upper through bolt to 85 ft-lbs.
(Torque the nut, not the bolt end).
Check the torque after 500 miles.
The bottom ball joint nut gets 60 ft-lbs.
Check the 4 bolts on the JBA holding the ball joint to verify 20 ft-lbs.
Wheel lugs are 85 ft-lbs.
Finish the job by pumping grease into all the fittings.
Pump grease into the ball joint until the boot begins to swell.

JBA gives a lifetime warranty. There are 3 grease fittings: one on the ball joint, and one at each end of the through bolt bushings.

Remove battery, tray under battery, bracket under battery.
Support front end, remove wheels.
Pull cotter pin on ball joint, then loosen/remove castle nut (19mm).
Hit flat spot provided for this with a hammer.
Then the ball joint should come loose.
Pull clips (special tool) to get plastic shields out of the way.
Pull abs line (9mm bolt) clip from the UCA.
Remove long bolt through UCA.
Remove UCA.
2 people are handy for one to hold the UCA and other to hold the bolt.
Note that you don't need a puller for this ball joint. Also note that you don't remove the ball joint thing from the knuckle as in the Gen3 video, you just reuse what is there.

Alignment

After installing new UCA you will want to get an alignment. Take it to a shop that specializes in aftermarket suspension work.

They adjust caster using the front cam on the lower control arm. This moves the lower arm forward/backward.

They adjust camber using the rear cam, which moves the lower arm in/out.

Before you even think of doing anything, mark the starting "baseline" position with a pain marker, drawing across frame and eccentric washers.

Lift will push the wheel back, so you may want to adjust caster to push it forward. This may have already been done if you had lift done with stock UCA. So if you install aftermarket UCA, the wheel may then be too far forward and you may need to move it back.

Torque spec for the cam bolts is 129 ft-lbs!!


Have any comments? Questions? Drop me a line!

Tom's Auto repair pages / tom@mmto.org