wADVr
Adventurer
I have noticed quite a bit of interest in swapping out the stock flares for aftermarket, larger cutout flares to accommodate larger tires and provide coverage. I would like to share the possibility of retaining the stock flares with up to a 35" tire yet still provide coverage and clearance. While not for everyone as the key is a combination of bump stops, wheel back spacing and fine tuning the link adjustments as well as suspension design. I was not willing to pay $400+ on a set of flares that IMO look somewhat awkward without massive tires under them.
I started with a set of 305/70R16(33x12) on effectively 3.75" back spaced wheels (rubi wheels + 1.25" spacers) and was able to cut very little of the flares. In the pictures I have attached you can see the trimming that was done. But as you can see the quality is not quite there I will explain a bit. The fronts were cut back ~1" front and back and basically the full inner lip so the tire can clear when turning left and right. Some trimming of the actual fender was needed as well as flattening out the seam on the firewall(this was not needed with the 33s) As for the rear I only had to cut the bumper side corners and again flatten out the seam on the rear of the wheel well (also not needed with the 33s) I did everything with a 4.5" angle grinder with a metal cut off wheel. The metal cut off wheel cut the plastic flare well but watch for melting plastic.
Below are the steps I took to make them fit without much work or expense:
So I started with adjusting the control arms for proper caster (4-5*) and found them to set the axle in the perfect spot in the wheel well to clear the firewall and the front of the wheel well. My intention was solely caster adjustment and got lucky with how it positioned the axle.
Next was the bump stops, I have sworn by 5" bump stop extensions for the front of an XJ with 33s for years but this jeep has JKS ACOS on it which has a lower, stiffer rubber stop for the frame side. So I settled for 4" of added bump stop height mounted on the axle. I used a JKS aluminum set on this project as it came with the vehicle but have used RE parts and even hockey pucks drilled and bolted down in the past. The most important part is testing to make sure that they make proper contact with the frame side rubber stop. Again I got lucky with my control arm adjustments that this worked out. For the rear I have used a set of DPG leaf spring plates and MJ sized Poly frame mounted stops. Not as critical as the front but still necessary.
The purpose of the build also needs to be taken into account. This build is not for hard core rock crawling and articulation but more of a balance for a well rounded trail rig that has no issue driving down the freeway. It has sufficient articulation for most any trail out there but not so much as to make removing half the fender necessary. That and I have realized that having a front suspension that articulates much more than the rear is not all that great on the trail especially on off camber situations. I currently have 10" travel shocks but would get full use from 12" travel.
The wheels made a big difference on getting the 35" tires to fit as there is no way this would have been possible with a 3.75" BS wheel. They did however work just fine with the 305/70R16s I previously was running. I found a deal on a set of AEV 16" bridger wheels which have 4.5" back spacing. This deal also came with an almost new set of 315/75R16 old style MTRs. I had no intention of moving up to a 35" tire but a new set of rubber sounded appealing as did the question of is it possible to fit them. The deeper wheels allow the tire to turn left and right without moving front and rear as much as a shallower wheel as the center of the tire is closer to the axis of the ball joints. The deeper back spacing also allowes the tires to tuck under the flares during articulation instead of running into them along with keeping the tires covered much better by the flare and keeping it legal.
Aside from the clearance issues the deeper back spaced wheels help with handling especially on the freeway. The jeep drives straighter with much less wander and seems to resist following cracks and ruts. Cornering is much more effortless as it holds the corner with almost no driver input. Before it would seem to push and constant attention was needed to keep it going in the right direction. I still hold true to my opinion that a 33" tire is the best size for an XJ and will be going back to a 33 once the novelty wears off and/or I can afford a new set of tires.
The only place the tires do rub are on the control arms. My control arms are RE short arms with drop brackets. I plan to move to something different that will have slightly more clearance around the tire so I can deal with the slight rub for now. This also I believe would be a non issue with 33s.
Hopefully I touched on everything but its late now so if therte is anything I left out post up.
I started with a set of 305/70R16(33x12) on effectively 3.75" back spaced wheels (rubi wheels + 1.25" spacers) and was able to cut very little of the flares. In the pictures I have attached you can see the trimming that was done. But as you can see the quality is not quite there I will explain a bit. The fronts were cut back ~1" front and back and basically the full inner lip so the tire can clear when turning left and right. Some trimming of the actual fender was needed as well as flattening out the seam on the firewall(this was not needed with the 33s) As for the rear I only had to cut the bumper side corners and again flatten out the seam on the rear of the wheel well (also not needed with the 33s) I did everything with a 4.5" angle grinder with a metal cut off wheel. The metal cut off wheel cut the plastic flare well but watch for melting plastic.
Below are the steps I took to make them fit without much work or expense:
So I started with adjusting the control arms for proper caster (4-5*) and found them to set the axle in the perfect spot in the wheel well to clear the firewall and the front of the wheel well. My intention was solely caster adjustment and got lucky with how it positioned the axle.
Next was the bump stops, I have sworn by 5" bump stop extensions for the front of an XJ with 33s for years but this jeep has JKS ACOS on it which has a lower, stiffer rubber stop for the frame side. So I settled for 4" of added bump stop height mounted on the axle. I used a JKS aluminum set on this project as it came with the vehicle but have used RE parts and even hockey pucks drilled and bolted down in the past. The most important part is testing to make sure that they make proper contact with the frame side rubber stop. Again I got lucky with my control arm adjustments that this worked out. For the rear I have used a set of DPG leaf spring plates and MJ sized Poly frame mounted stops. Not as critical as the front but still necessary.
The purpose of the build also needs to be taken into account. This build is not for hard core rock crawling and articulation but more of a balance for a well rounded trail rig that has no issue driving down the freeway. It has sufficient articulation for most any trail out there but not so much as to make removing half the fender necessary. That and I have realized that having a front suspension that articulates much more than the rear is not all that great on the trail especially on off camber situations. I currently have 10" travel shocks but would get full use from 12" travel.
The wheels made a big difference on getting the 35" tires to fit as there is no way this would have been possible with a 3.75" BS wheel. They did however work just fine with the 305/70R16s I previously was running. I found a deal on a set of AEV 16" bridger wheels which have 4.5" back spacing. This deal also came with an almost new set of 315/75R16 old style MTRs. I had no intention of moving up to a 35" tire but a new set of rubber sounded appealing as did the question of is it possible to fit them. The deeper wheels allow the tire to turn left and right without moving front and rear as much as a shallower wheel as the center of the tire is closer to the axis of the ball joints. The deeper back spacing also allowes the tires to tuck under the flares during articulation instead of running into them along with keeping the tires covered much better by the flare and keeping it legal.
Aside from the clearance issues the deeper back spaced wheels help with handling especially on the freeway. The jeep drives straighter with much less wander and seems to resist following cracks and ruts. Cornering is much more effortless as it holds the corner with almost no driver input. Before it would seem to push and constant attention was needed to keep it going in the right direction. I still hold true to my opinion that a 33" tire is the best size for an XJ and will be going back to a 33 once the novelty wears off and/or I can afford a new set of tires.
The only place the tires do rub are on the control arms. My control arms are RE short arms with drop brackets. I plan to move to something different that will have slightly more clearance around the tire so I can deal with the slight rub for now. This also I believe would be a non issue with 33s.
Hopefully I touched on everything but its late now so if therte is anything I left out post up.
