Upper control arms

[jwiereng]

Seems to be consensus that new UCA are recommended when using lift higher than 2.5 inches on the 4Runner/taco.

New UCA allow the alignment adjustments to be made to put caster and camber in optimal spec

How specifically is this accomplished?
What is different about the geometry?
Is the pivot point further inboard? And if so, by how much?

Do all aftermarket UCA use the same pivot location?

How much weight is born by the UCA? Outside of different ball/uniball joints what benefit beyond geometry do new UCA provide?

Is it possible to chop and weld OEM UCA to correct geometry for a mild lift?

 

[smokeysevin]

Seems to be consensus that new UCA are recommended when using lift higher than 2.5 inches on the 4Runner/taco.

New UCA allow the alignment adjustments to be made to put caster and camber in optimal spec

How specifically is this accomplished?
The outer ball joint pivot point is moved

What is different about the geometry?
Caster change is handled by shifting the ball joint pivot point forwards or backwards, the camber curve is changed by lengthening or shortening the distance from the UCA pivot to the ball joint

Is the pivot point further inboard? And if so, by how much?
Not sure

Do all aftermarket UCA use the same pivot location?
Pretty much, there is only so much you can tweak the pivot distance without messing up the camber curve or running out of lower control arm alignment range.

How much weight is born by the UCA? Outside of different ball/uniball joints what benefit beyond geometry do new UCA provide?
Most aftermarket arms are chromoly tube which is probably substantially more durable than the stock stamped steel parts. The biggest benefit is swapping to a uniball which is much stronger than the stock ball joint. You get extra wheel travel because the ball joints don't bind up and limit your droop.

Is it possible to chop and weld OEM UCA to correct geometry for a mild lift?
You could probably cut and weld a stock arm but I would advise against it. It is super easy to accidentally introduce loads of bumpsteer or even worse, to have the joint fail and have your truck go rolling.

I replied in red.

Sean

 

[Tex68w]

I don't think anyone would ever recommend chopping up and welding a stock UCA as an alternative to buying an aftermarket option. The steel used on the stock UCA is quite thin and usually open on the bottom. SPC and JBA are likely your most cost efficient options.

 

[DaveInDenver]

When you increase the ride height of an IFS truck the geometry changes of the control arm pivots and spindle. It would normally happen as the suspension cycles but you wouldn't notice because being extended its not a normal position but the suspension loses caster as it extends. The effect of negative caster is to make the steering more reactive, normally what you'd call "twitchy", e.g. over sensitive.



You can adjust this to some extent using the cams on the lower arms. There's a couple of issues with this. First, adjusting the cams for caster also affects camber especially, so it's a balancing act. Since Toyota assumed a static ride height the adjustment is relative to that expectation.




What aftermarket upper arms do is add in caster to the baseline, sort of pre-caster'ing the arms. If you put the suspension at the same ride height as stock with these arms you'd make it seem slower to react to steering input and the road.



I personally run Camburg who say they add 3° of caster compared to stock to compensate. I run the ball joint style Camburgs, which use stock ball joints or in my case I'm using the MOOG aftermarket replacements since Toyota does not sell ball joints as a replacement item (you have to buy complete upper arms from Toyota). The reason I run these is uniballs in the snow and winter aren't ideal and require extra maintenance to prevent from pitting and squeaking. It's just a matter of convenience for me.

 

[jwiereng]

Thanks for all the replies and good info.

UCA (and all parts) are pretty dear after doing the USA —> Canada exchange.

SPC $500+

JBA $595

 

[Tex68w]

Thanks for all the replies and good info.

UCA (and all parts) are pretty dear after doing the USA —> Canada exchange.

SPC $500+

JBA $595

That's still less than Icon, Total Chaos, Camburg, etc.

 

[DaveInDenver]

My Camburg ball joint UCAs were US$529. I have nothing to complain about with them but if I was buying a set now it probably would be JBA.

 

[smokeysevin]

I have had my camburg arms since 2009 and put more than 150k miles on them. They just got new bushings and uniballs like 6 months ago but have been flawless.

Buy well made parts, especially when it comes to suspension or brakes.

Sean

Sent from my LM-G710 using Tapatalk

 

[blueranger501]

Had my camburgs since 2004 and 140k. 1 uniball rebuild. If I were spending the money I wouldn’t want to go with ball joints again.