JBA UCA Running 285/70/15? Anyone doing it?!

[Sir.T.Grant]

Evening, quick question for the masses. I have a 2018 4Runner with and Ironman 4x4 suspension lift (3.2 in front, 2.7 inch rear) and I have come to the conclusion I need to upgrade my UCAs (sometimes at speed the tire will grip and jerk left/right, the steering does not feel tight).

I like the JBA UCA because of their price point but I am fearful of running 285-70-17s (Michelin LTXs) with that UCA.

Has anyone had any experience with that combo? I am I just over thinking everything?

 

[ahtoxa11]

I don’t quite follow the description of what’s happening at speed. How does the tire grip suddenly? Is this on the road?

Also, 3.2 inches is a ton of lift, even on aftermarket UCAs. At this point the geometry is bad and will probably cause all sorts of driving weirdness, not to mention bad CV angles and little down travel.

Any known UCA will work with the tire size you listed. That’s really not an issue I’ve ever heard of, but if you bring the front down under 3” you will have a better experience, I think.

 

[rayofsi]

i had jba running 285/75/r17, if you are running 15 inch wheels, you might have some big issues. but i believe the 15 part is a typo.

with the jba. i did experience some tire rub. so yes there is something to worry about.

 

[JP421]

Evening, quick question for the masses. I have a 2018 4Runner with and Ironman 4x4 suspension lift (3.2 in front, 2.7 inch rear) and I have come to the conclusion I need to upgrade my UCAs (sometimes at speed the tire will grip and jerk left/right, the steering does not feel tight).

I like the JBA UCA because of their price point but I am fearful of running 285-70-17s (Michelin LTXs) with that UCA.

Has anyone had any experience with that combo? I am I just over thinking everything?

285's on stock off road rims will rub the UCA's some. Spacers will help but can cause rubbing in other areas. I currently have JBA's with 285's on stock off road's and spacers. Had to do BMC and fender lining trim.

 

[Sir.T.Grant]

285/70/17 not 285/17/15

Sorry for the typo, I am looking to run 285/70/17s.

I understand the JBA UCA has some rubbing issues with 285/70 on 17in stock rim.

1) Is there a rim that can facilitate this tire without rubbing on the UCA?
2) Is there a different UCA that I can purchase to mitigate the rubbing risk of the JBA
3) If 1 & 2 are not viable, what suggestions do you have for largest tires I can run. I have looked endlessly for 275/70 but Michelin does not appear to make them any longer...

To answer your driving stability questions. When driving at speed (~35mph) if I encounter any road imperfections the wheel will "grab" and pull to that direction. I can also hear the tires squeak when i negotiate a major left or right hand turn at speed. Overall the steering does not feel as strong or firm as what it once was... I don't know if that clears anything up but my South Carolina education precludes from a better explanation without the use of finger-paint...

 

[JP421]

You could just add spidertrax spacers or wheels with higher negative offsets.

 

[ads2539]

To answer your driving stability questions. When driving at speed (~35mph) if I encounter any road imperfections the wheel will "grab" and pull to that direction.

Re. the grabbing and pulling, I think the traction control is kicking in.

 

[Sir.T.Grant]

Rims with Higher Negative Offsets

Suggestions or specific numbers of rims with Higher Negative Offsets? Is this going to cause the UCA rub to be transferred to some other portion of the wheel well?

 

[Charlievee]

Have you looked at the rim/tire recommendations on the JBA website?

 

[JP421]

Suggestions or specific numbers of rims with Higher Negative Offsets? Is this going to cause the UCA rub to be transferred to some other portion of the wheel well?

You're going to have to do some trimming\modification in the wheel well with 285's regardless.

The 1.25" spidertrax spacers will do it, 1.25" spacers is about equivalent to running -32 offset, though anything -10 and over looks like it should do it.

If you want simpler just go with 275's. The Falken Wildpeaks are very good tires that are available in 275/70/17.

 

[daytonaviolet]

I did this with stock trd pro wheels. I had rubbing on rear of bumper (trim and push liner forward) and mud flaps (removed). Caster 4+. I didn’t rub on UCA but I did add spidertrax to get the poke.

 

[ragin_cajun]

Re. the grabbing and pulling, I think the traction control is kicking in.

No one has mentioned it, but I would check your ABS sensor wiring. This is a common issue after lifting if someone pulled on the wiring harness too hard. It could be momentarily triggering ABS or traction control. You shouldn't have a random UCA rub going straight down the road.

 

[daytonaviolet]

No one has mentioned it, but I would check your ABS sensor wiring. This is a common issue after lifting if someone pulled on the wiring harness too hard. It could be momentarily triggering ABS or traction control. You shouldn't have a random UCA rub going straight down the road.

If this happens, will there be a light on the dash ?

 

[85GT-79FJ40]

That much lift and stock uppers I bet your alignment is pretty out of whack. But it shouldn't be jerking the wheel if it's even remotely correct. I have JBA arms and 285's with no issues but I run 17x8.5 Method wheels with 0 offset. I did do a body mount chop too. They were stuffing the mounts pretty bad. Actually hit with 265's and stock trail wheels with 1.25" spidertrax spacers too.

 

[Johnnyg182]

I lifted my 19 pro 2” in the front and put on SPCs. No rub on UCA with stock pro wheel and 285/70. No rub anywhere else either even when crawling over rocks. Pretty happy but miss the spacer look and wish I got 285/75s. Shop was supposed to put my 285s on and do a BMC but they ran out of time for the BMC and removed my spacers. The shop talked me out of doing JBA and into the SPCs. I also destroyed an abs wire doing the suspension install. They are so damn sensitive!

 

[calicojones]

285's on stock off road rims will rub the UCA's some. Spacers will help but can cause rubbing in other areas. I currently have JBA's with 285's on stock off road's and spacers. Had to do BMC and fender lining trim.

Could you tell me what size spacers you ran with the 285s on stock off road rims?