Fenders, spacers and 37's

[darylm74]

I have a 2021 JKU diesel Willy's. I decided to grab 37's on the BB Online deal that was posted earlier. I have a 2.5" Rock Krawler lift that is in my garage and I hope to get installed in the next couple of weeks. I had 35's on my JKU Sahara with a similar lift with no rubbing. I think the 37's are going to rub. What should I be looking for? Looks like the new/trimmed finders are the first consideration. Do I need to change out the inner fenders as well? Spacers seem to be a possibility. I don't rock crawl but have done a little of the the Citrus Wildlife trails in Florida.

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[Bandit59]

I have a 2021 JKU diesel Willy's. I decided to grab 37's on the BB Online deal that was posted earlier. I have a 2.5" Rock Krawler lift that is in my garage and I hope to get installed in the next couple of weeks. I had 35's on my JKU Sahara with a similar lift with no rubbing. I think the 37's are going to rub. What should I be looking for? Looks like the new/trimmed finders are the first consideration. Do I need to change out the inner fenders as well? Spacers seem to be a possibility. I don't rock crawl but have done a little of the the Citrus Wildlife trails in Florida.

Might want to look at your gearing

 

[darylm74]

Might want to look at your gearing

My understanding is with the diesel, I should be OK with the 37s. It doesn't bog down as bad.

 

[jhackathorne]

If you are on a 2.5" lift and 37's and not flexing out, you are fine on stock fenders and liners. I am on a 2? Synergy lift and 37's and even when rock crawling I only occasionally will rub my fenders.

 

[bjm00se]

Install the lift and tires, and go from there.
Keep in mind the lift also increases your basic bump stop, which also creates more room for tires.

 

[LCW]

Bump stops. 2.5-3” front. 3-3.5” rear.

Edit: this is on a regular Rubicon. Subtract however much extra bump stop XRs came with.

 

[Bandit59]

My understanding is with the diesel, I should be OK with the 37s. It doesn't bog down as bad.

If it has 345 gears. They r not very strong. They want to try to get as much mpg as possible gearing in the 400s is so much better with bigger tires and wheels

 

[darylm74]

If it has 345 gears. They r not very strong. They want to try to get as much mpg as possible gearing in the 400s is so much better with bigger tires and wheels

I have the 3.73 gears in my Willy's. What I have read so far is that the 4.10 is not noticeable enough of a jump to matter and 4.56 is too much. My thoughts were to try it out and regear if necessary. I had 35's on my JK with a gas engine and regeared, but also put in an ARB locker that point. It was definitely a big notice there as it was a 2011 and the 6 cyl in the earlier JKs sucked from my experience. Luckily my JL is just a back-up for my wife's aging car, quick trips to the store and some weekend fun. I work from home so not driving miles like I did with my JK. If I have to re-gear I will probably do some locker work up front too while I am "under the hood."

 

[JT1]

I have a 2021 JKU diesel Willy's. I decided to grab 37's on the BB Online deal that was posted earlier. I have a 2.5" Rock Krawler lift that is in my garage and I hope to get installed in the next couple of weeks. I had 35's on my JKU Sahara with a similar lift with no rubbing. I think the 37's are going to rub. What should I be looking for? Looks like the new/trimmed finders are the first consideration. Do I need to change out the inner fenders as well? Spacers seem to be a possibility. I don't rock crawl but have done a little of the the Citrus Wildlife trails in Florida.

Gearing wise you are likely fine.
I have no idea how much lift the RK will get you on a diesel, but will likely be more than 2.5". You will probably be fine on road, but will probably rub off road when disconnected. You will need new wheels or wheel spacers to keep the tires off your LCAs and swaybar endlinks.

 

[BDinTX]

Hey Daryl, I've got a diesel Rubicon and recently put 37x12.5x17 on wheels with a 0mm offset. I don't recall factory wheel offset but these do push the wheel slightly outboard. I'm also don't know if the Willys has the wider axles. All diesels got 3.73 gears which I think are fine with this engine and tire size. It's still plenty quick from a stop and freeway cruising still sees 8th gear.

I did a few emergency stop tests on road at about 60mph and I wasn't concerned with braking. Only offroad, like trying to ease down ledges, do I have to apply noticeably more pedal pressure, and lower gears really won't help you there.

Diesels (and XR and 392) also get 1 3/8" more bump stop over other models. I added 1/2" of bump stop but flexed out I was still rubbing at the top of the fender liner so I plan to add another 1/2". Not sure what fenders Willys come with but if they're lower I'd start there. Also worth mentioning, some lift manufacturers don't account for the increased bump on diesels in either their bump extension or instructions.

 

[Maverick909]

here is a good reference. i started with a base sportS model.. I swapped in rubicon axles ( i wanted front and rear lockers) and did a jks Mfg 2.5" lift. i have method wheels with 4.75" back spacing, 37" x12.5 ' Patagonia Mt-02 and changed the fenders and inner liners and i still get minor rub at full flex. Nothing that stops me from completing hard trails at all. you can see the front stuffs really nicely rear doesnt stuff as nicely as the front but it does kiss the inner fender liner even with them being aftermarket. only thing i dont know about is if the diesel axles come in the short or wide

 

[darylm74]

My axles are the M210 Front and M220 Back according to my build sheet. Not sure how to tell if it is narrow or wide but my understanding is they are the same as the Rubicon. The RC lift I have is for the diesel with the heavier front springs so I should get a true 2.5" lift. I plan to use the MOAB wheels that came on it so will have to adjust backspace based on those. Unfortunately the Willy's doesn't come with the two piece fenders that the Sahara and Rubicons do. I have been looking at aftermarket as well as maybe picking up some Rubicon fenders in the local area. I can't go into a grocery store parking lot without seeing 10 jeeps or more in my area (most of them Rubicons) so hoping someone that did some mods wants to get rid of them cheap.

 

[darylm74]

A little research says it is a narrow D44. I assume that is front and rear. Sucks but will require some further adjustment.

 

[darylm74]

On another note, I have the RC bump-stop kit which allows me to adjust so thinking that will play into the mix. I swear Jeep Mods are like Legos

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