4" JBA LIFT?

Kjtrailrider · **Joined:** Sun May 13, 2007 9:00 pm **Posts:** 28

hey everyone ive been looking at lift options with my kj and wanted to know a couple things about the jba..do i need to upgrade my gears or axles with this lift, and will the springs on this kit be able to run both front and rear bumpers without sagging?

Sport · **Posted:** Tue Apr 07, 2009 4:25 pm

Kjtrailrider wrote:

hey everyone ive been looking at lift options with my kj and wanted to know a couple things about the jba..do i need to upgrade my gears or axles with this lift, and will the springs on this kit be able to run both front and rear bumpers without sagging?

I would contact Marlin at JBA.

Gears depend on what tires you want to run.

jsc7002 · **Posted:** Tue Apr 07, 2009 4:39 pm

you pretty much need to regear with any lift if you are planning on running 31" or bigger tires.

KJ04 · **Posted:** Tue Apr 07, 2009 5:54 pm

Adding a lift does not require regearing.

Running a 255/70/16 (30") or a 245/75/16 (30.6") does not require regearing. You will only lose a small amount of MPG's and a little power and hardly worth the cost of regearing.

32" tires, you may want to concider regearing.

E2 · **Posted:** Sat Mar 13, 2010 9:42 pm

to figure gearing out someone told me this:
Do a ratio of old tire diameter to new tire diameter and multiply times old ratio. Round it off and go to the closest standard gear ratio.

But what does that mean?

225/75r16 (29.3") stock
265/75r16 (31.7") what I want

dieselenthusiast · **Posted:** Sun Mar 14, 2010 12:45 am

Kjtrailrider wrote:

hey everyone ive been looking at lift options with my kj and wanted to know a couple things about the jba..do i need to upgrade my gears or axles with this lift, and will the springs on this kit be able to run both front and rear bumpers without sagging?

I would personally buy the Frankenlift Premium II kit with the CRD OME coils if you plan on a front and rear bumper. The JBA 4” isn’t much taller than the Frankenlift with the extra rear isolators. And more importantly, the Frankenlift will be as good of quality if not better quality than the JBA 4” and a whole lot cheaper. Save the cash for a front and rear bumper, winch, lockers, gears, etc. I would install 4:10’s if you plan to run a 30.5” tire or taller.

E2 · **Posted:** Sun Mar 14, 2010 12:57 am

dieselenthusiast wrote:

Kjtrailrider wrote:

hey everyone ive been looking at lift options with my kj and wanted to know a couple things about the jba..do i need to upgrade my gears or axles with this lift, and will the springs on this kit be able to run both front and rear bumpers without sagging?

I would personally buy the Frankenlift Premium II kit with the CRD OME coils if you plan on a front and rear bumper. The JBA 4” isn’t much taller than the Frankenlift with the extra rear isolators. And more importantly, the Frankenlift will be as good of quality if not better quality than the JBA 4” and a whole lot cheaper. Save the cash for a front and rear bumper, winch, lockers, gears, etc. I would install 4:10’s if you plan to run a 30.5” tire or taller.

What is the amount of lift you get from the Frankenlift Premium II kit??
With the 4" JBA I have 4.5 to 4.75 lift in the rear and right now 4" in the front but can adjust it higher.

dieselenthusiast · **Posted:** Sun Mar 14, 2010 1:03 am

E2 wrote:

What is the amount of lift you get from the Frankenlift Premium II kit??
With the 4" JBA I have 4.5 to 4.75 lift in the rear and right now 4" in the front but can adjust it higher.

You can get 4" pretty easy

JeepinJarhead03 · **Posted:** Sun Mar 14, 2010 2:09 am

part of the loss of power isn't entirely the diameter change but the weight of the tire when switching from P's to E's for instance

i went from 255-70 michelin style AP street tires to 245-75 E M/T's which is very little difference in dia of the tires even if you roll them out, and i can tell a difference, not a huge difference but there's a difference

daspes · **Posted:** Sun Mar 14, 2010 3:09 am

E2 wrote:

What is the amount of lift you get from the Frankenlift Premium II kit??
With the 4" JBA I have 4.5 to 4.75 lift in the rear and right now 4" in the front but can adjust it higher.

There was a thread way back when the first JBA 4" lifts hit the market. A stock Frankenlift (no clevis or rear iso's) was about 1/8"-1/4" lower... For less than half the price.

E2 · **Posted:** Sun Mar 14, 2010 3:41 am

daspes wrote:

E2 wrote:

What is the amount of lift you get from the Frankenlift Premium II kit??
With the 4" JBA I have 4.5 to 4.75 lift in the rear and right now 4" in the front but can adjust it higher.

There was a thread way back when the first JBA 4" lifts hit the market. A stock Frankenlift (no clevis or rear iso's) was about 1/8"-1/4" lower... For less than half the price.

Too bad they are not selling the Frank's for the KK.

pg2676 · **Posted:** Fri Mar 19, 2010 11:45 pm

Am I going to need a lift to run 265/65-17 tires?

daspes · **Posted:** Fri Mar 19, 2010 11:53 pm

pg2676 wrote:

Am I going to need a lift to run 265/65-17 tires?

Yes, that size is a 30.6" tire. Anything over 29.5" (245/70/16 or 245/65/17) requires a lift.

E2 · **Posted:** Sat Mar 20, 2010 11:32 am

pg2676 wrote:

Am I going to need a lift to run 265/65-17 tires?

Without rubbing you need a lift. A 30.5" tire is more like for a 2" lift kit or the 2.5" lift. The think you need to ask yourself is what your final goal is. Is it to just get some bigger tires? If so then spending money on the 2.5" may not suit you. I spacer lift is a lot less, well upfront. You will need to replace your springs and shocks soon. But I bet you can PM one of us that have changed out ours for the JBA lifts for less than you can get at the dealership. The JBA lifts give you much more than just height. The ride is very nice on the highway and around town. The springs are stiffer when offroad so you don't bottom out. You get more travel with the kit to keep you tires connected to the ground. I hope this helps I am no expert but my thoughts. I have the 4" lift and it's great!

4" JBA LIFT?

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