When are UCA’s really needed?

Bird dog

= V • Platinum
T3G Supporter
Messages
527
Location
Peoria,AZ
First Name
DJ
Military
Navy
T3G Member
#659
I’m going with OME suspension with 255/85r16 tires. Do I have to replace the UCA’s?
 

0uTkAsT

= VII • Aficionado
T3G Supporter
Messages
1,281
Location
Gilbert, AZ
First Name
Josh
T3G Member
#646
There's a difference between necessity and just doing it because it's the right way to do it. You should, yes. You will only gain wheel travel from your setup and gain additional caster if you use aftermarket UCAs, as well as adding strength and reliability to the whole system at the same time.

That being said, I suppose you don't *need* them if you're able to get it aligned properly without... In that case, you may choose to stick with the stock UCAs at the expense of all of the above.
 

Tyler

= IX • Paragon
Badministrator
T3G O.G.
Messages
5,859
Location
Long Island, NY
First Name
Tyler
Military
Marine Corps (Vet.)
Build Thread
(Click to View)
T3G Member
#1
I’m going with OME suspension with 255/85r16 tires. Do I have to replace the UCA’s?
With this question I generally ask one thing first: Is the money the deciding factor for you?

If it absolutely is, you don’t need them.

But if you afford it (they’re not that much more expensive), you defintely should for the reasons 0uTkAsT mentioned. Doing the lift and tires is the best time to do the UCA’s and will totally help with potential tire rub.

Similarly, the ECGS bushing to replace the carrier bearing in your front diff is not needed, but it’s a cheap investment with a large benefit, so you should do that now as well.
 

0uTkAsT

= VII • Aficionado
T3G Supporter
Messages
1,281
Location
Gilbert, AZ
First Name
Josh
T3G Member
#646
With this question I generally ask one thing first: Is the money the deciding factor for you?

If it absolutely is, you don’t need them.

But if you afford it (they’re not that much more expensive), you defintely should for the reasons 0uTkAsT mentioned. Doing the lift and tires is the best time to do the UCA’s and will totally help with potential tire rub.

Similarly, the ECGS bushing to replace the carrier bearing in your front diff is not needed, but it’s a cheap investment with a large benefit, so you should do that now as well.
Good point on the bushing!
 

BlueFalconActual

= IV • Gold
T3G Supporter
Messages
86
Location
SoCal
Military
Marine Corps
T3G Member
#774
I didn't replace mine when I did my "lift" but that's because I only leveled it out in the front by 1 inch and I was trying to keep the price down because divorces are really expensive.
That being said, I plan to replace them down the road because it is the best way to do it.
 

Bird dog

= V • Platinum
T3G Supporter
Messages
527
Location
Peoria,AZ
First Name
DJ
Military
Navy
T3G Member
#659
Again, thanks. I am convinced. UCA’s do not need to be replaced, but without the upgrade you aren’t able to use the full potential of the suspension.
Your input really was a help guys. What I want to do is get it dialed in once, so I don’t have to fuck with it. I like the trail more than shop work.
 

951_yota

= V • Platinum
T3G Supporter
Messages
327
Location
Socal
First Name
Travis
Military
Air Force (Vet.)
T3G Member
#405
Again, thanks. I am convinced. UCA’s do not need to be replaced, but without the upgrade you aren’t able to use the full potential of the suspension.
Your input really was a help guys. What I want to do is get it dialed in once, so I don’t have to fuck with it. I like the trail more than shop work.

Someone is selling lr ucas for 375$. I have ome and first did not get then. After horrible alignments i quickly bought them and it fixed it immediately. Also allows me 33’s no rubbing.
 

ROCdermody

= II • Bronze
Messages
18
First Name
Steve
T3G Member
#759
There's a difference between necessity and just doing it because it's the right way to do it. You should, yes. You will only gain wheel travel from your setup and gain additional caster if you use aftermarket UCAs, as well as adding strength and reliability to the whole system at the same time.

That being said, I suppose you don't *need* them if you're able to get it aligned properly without... In that case, you may choose to stick with the stock UCAs at the expense of all of the above.

This is interesting to me. I've never heard the connection between aftermarket UCAs and suspension travel. I have stockers with 2.5"ish lift and 285/75R16s. I get some rub at full compression and steering lock, and my alignment is (just) inside the green window, but was unaware travel was being limited by the stock UCAs.

Do you mind expanding on that?
 

0uTkAsT

= VII • Aficionado
T3G Supporter
Messages
1,281
Location
Gilbert, AZ
First Name
Josh
T3G Member
#646
This is interesting to me. I've never heard the connection between aftermarket UCAs and suspension travel. I have stockers with 2.5"ish lift and 285/75R16s. I get some rub at full compression and steering lock, and my alignment is (just) inside the green window, but was unaware travel was being limited by the stock UCAs.

Do you mind expanding on that?
Sure, this is where the "mid" in "mid travel" comes from:
Standard travel = stock arms,
Mid travel = aftermarket UCAs,
Long travel = aftermarket UCAs and LCAs.

In a nutshell, lifting IFS changes the geometry of the arms and raises the angles of the joints. This causes binding, usually at droop or sometimes they're effectively maxed out at ride height. On top of the aftermarket arms correcting this geometry for lifted applications, the joints themselves offer significantly greater range of motion. The OEM arms have about a 45- to 50-degree range of motion, uniballs typically fall in the 55- to 65-degree range, and the best ball joints on the market offer 80- to 90-degree range of motion. This allows the suspension to articulate freely rather than binding.

Obviously travel is not just a function of the joints, suspension geometry, shocks and spring length, etc. It's all part of the same system so you have to know how everything interacts with each other in order to get the desired results right down to the brake lines and CVs and wiring and stuff that you wouldn't otherwise consider being a limiting factor.
 
Last edited:

ROCdermody

= II • Bronze
Messages
18
First Name
Steve
T3G Member
#759
Sure, this is where the "mid" in "mid travel" comes from:
Standard travel = stock arms,
Mid travel = aftermarket UCAs,
Long travel = aftermarket UCAs and LCAs.

In a nutshell, lifting IFS changes the geometry of the arms and raises the angles of the joints. This causes binding, usually at droop or sometimes they're effectively maxed out at ride height. On top of the aftermarket arms correcting this geometry for lifted applications, the joints themselves offer significantly greater range of motion. The OEM arms have about a 45- to 50-degree range of motion, uniballs typically fall in the 55- to 65-degree range, and the best ball joints on the market offer 80- to 90-degree range of motion. This allows the suspension to articulate freely rather than binding.

Obviously travel is not just a function of the joints, suspension geometry, shocks and spring length, etc. It's all part of the same system so you have to know how everything interacts with each other in order to get the desired results right down to the brake lines and CVs and wiring and stuff that you wouldn't otherwise consider being a limiting factor.

Thanks for spelling that out. It hadn't occurred to me that there would be that big a difference in range of motion between the two.
 

eldedo

= II • Bronze
Messages
27
First Name
jim
T3G Member
#562
Side note, stock alignment numbers go out the window when you lift. In particular is caster, typically target around 4°.
 
Top Bottom