planman

I've received a few questions about how to do this.

This information has been repeated several times in other threads via copy and paste.

I thought it would be easier for people to find if it was a stand alone thread.

Wheels with more backspacing require slightly more bumpstopping.

The pics below show 17" wheels with 4.5" backspacing and 15" wheels with 4" backspacing. The 4.5" backspaced wheels required more steering stop washers and slightly more front extended bumpstopping.

With flat flares and a 1" body lift, to run 37s you want 0"-1" front and 2.5" rear extended bumpstops.

If you want to do 37s with flat flares and no body lift, you want 1.5"-2" front and 3.5" rear extended bumpstops. If you want to run shorter rear bumpstops--i.e. 2.5" in the rear--you need to generously trim the front and rear pinch seams of the rear fender well.


As a preface, lift height alone does not give you the ability to run larger tires.

What matters is flare/body clearance and the length of your bumpstops.



So, here is an explanation:

In the pictures below, I have my winter wheels on...with a OME LT kit (3") from Northridge4x4.

(I haven't reinstalled my wide Xenons for winter yet.)





Okay, the details on how to do it:

37s, OME HD springs (3"), 1" body lift, and:

Cut 2" off stock Rubi rocker guards




Drill holes to replicate stock rocker guard ends so you can move the caps (here is what a stock end looks like):




Fold over pinch seam with BFH (big friendly hammer), sand underneath cut or flat flares, paint flat black, also sand rear most pinch seam and paint it flat black so the 1" body lift is less obvious. Sand inner rear fender well and paint with Duplicolor bedliner (looks better than trimmed stock inner liner):




Sand and paint flat black under the front trimmed flares, and drill a couple small holes through the bottom part of the front inner fender liner so you can zip tie it to the body mount to hold it in place:





You will need 2.5" extended rear bumpstops. Here are mine from my original 2.5" TF BB when I had my Xenons installed:





You can run stock front bumpstops without rubbing, but your springs will fully compress. I later added 1" extended front bumpstops from JKS (the kind that you bolt to the bottom of the front spring perch). Here is a full stuff on stock front bumpstops and 37s (pre-OME LT shocks and extended brakelines):



Barely touched with compressed front bumpstops and Xenon flares:





Wife driving with front compressed on stock bumpstops:




Wife also driving with stuffed rear tire (those tires and wheels are now on her rig):





Install front axle sleeves, C gussets, box in lower control arm brackets with skids, and reinforce trackbar bracket on front axle:







Install chromoly front and rear axle shafts (didn't take any pics).

Install minimum 5.13 gears, and preferably 5.38 gears if you have an automatic (no install pics).

Install Superchips Flashpaq.

Adjust front steering stops with 4-6 washers to avoid rubbing tires on frame rail with full lock turn. Not my pics, but here is is a write-up:

Project-JK.com - Jeep JK Wrangler Resource Jeep JK Wrangler Steer Stop Adjustment


Here are the results with the upgrade from the 2.5" Teraflex BB, with 4dr Rubi take-off front springs, and Skyjacker Hydro shocks for a 2.5" to 3" lift...

to the current OME HD 3" springs with OME long travel shocks, extended brakelines, Currie front lower adjustable arms, JKS adjustable front trackbar, Rubicon Express rear adjustable trackbar, JKS rear upper adjustable control arms, JKS 1.25" front extended bumpstop, and keeping the 2.5" rear Teraflex extended bumpstop:






And from the 2010 EJS:

MrChuckles

Nice rig man!

Gman*2007

That sure is a nice rig and great rocky mountain view.

RodRecket

Read one of your threads (like this one) over a year ago and it was my guide to building up my rig. Thanks for sharing....and for so everyone knows it works (even though im stuck):

Dyipney

Question for PlanMan - does it matter whether you get the TF upper or lower bumpstop extensions? Are both needed, or can I just get the uppers for both front and rear?

Many thanks for your great write-ups!

planman

Thanks.

I recommend the rear lowers.

The front uppers work, but they are more than is needed for 37s with flat flares. So, front lowers that are shorter will allow more suspension travel.


Sent from my iPad using Tapatalk HD

pjmjk

great explanation answered quite a few questions i had

WARLOCK

Question:

If you replace the rear control arms with adjustable ones to properly center the rear tires in the wheel well when fully flexed, you trim the pinch seems and you replace the rear bumper, do you think you could run with smaller bumpstop in the rear ?

On your pic that shows the rear wheel fully flexed it looks like it would benefit from moving about 1'' to the back, but you would have to replace the rear bumper.

It seems also that you have plenty of up space to flex even more, that's why I'm asking.

xEnron

I'm about to pull the trigger on new wheels and tires, and am looking for thoughts on my setup. First, this vehicle is my DD... I do not wheel. My JKUS is how I get to work... It's also how I get to the mountain for skiing... the beach... the campground... It spends the summer topless. It gets me where I want to go, when I want to go, regardless of weather. Always on a road. That being said... It's a 2008 JKUS automatic with a 3.8 L and 3.73. It has a TF 2.5 lift. The wheels I'm looking at have 4.5 BS. Tires will be 37" ATs. I will be cutting the pinch seams. I also plan on upgrading gears to 5.13 in the near future. Is this configuration doable? Are extended bump stops needed if I don't wheel?

planman

If you trim the entire radius of the rear fender well pinch seams and run the right sliders and rear bumper, you can run smaller bumpstops in the rear.