WaterRat72

JKUR.. 3" lift, flat fenders, spacers, currently running 4.10 gears with 35's on stock D44's.

My question is, I would like to run 37's next time around when the current rubber wears out. Can I do so with the current axles, gearing or would I have to switch to D60's with something like 4.56 or 4.88's? Or should I just leave it the hell alone and keep it as is?

I drive it daily and wheel occasionally mostly overland type stuff for camping. It's always gotten me where I need to go I just figured 37's might do it that much easier.

I suppose another thing I would have to think about is possible clearance issues?

Opinions?

davegus

At a minimum, you'll need to cut the Rubicon rock sliders a little - about a couple inches in the rear. You'll also need to trim the body pinch seam. No big deal, everyone does it. A simple sawsall with a metal cutting blade is all you need. Your tires will rub the stock fender flares when your shocks compress upward. Not a big deal, just annoying.

Gears- I'd recommend 5.13 at a minimum. 5.38 if you live at high elevation or intend to do some serious hill and rock climbing.

Axle- stick with the D44 for what you described. D60 is overkill for you.

nthinuf

Which engine? Which transmission? Typical freeway speeds/duration? Whatever else you can think of. Hard for people to give suggestions on gears without knowing more. (ex, davegus gave a suggestion based on his 3.8, and many people with a 3.6 might disagree...)

Just light overlanding, on forest service type roads? If that's the case, 60's are probably overkill. Leave the axles alone until you can form your own opinion on the performance with 37's, and you've had a chance to read more opinions on the various options for strengthening the front housing.

bl17z90

You can run 37's with that setup, especially if you have a 2012+ with a manual, even an auto. But a deeper gear ratio like 4.88 or 5.13 would be more desirable.

resharp001

Agree with all the comments above. I'd add that I ran 37's on 4.10 gears for about a year. It's doable, but it will really wear you down over an extended period. I regeared to 5.13s on my 3.6L auto. Probably a little aggressive for most, but I love it.

larry0071

I agree with above: The Rubicon Rock Slider needs cut on the rear.

I disagree and agree with the pinch seam, there was a change in 2013 sometime where the "shark fin" was factory cut, on my 2014 I run STT Pro 37x13.5 tires with no body cuts, full factory flares and wheel tub liners in place. It is model year dependent if you need to trim or not.

I have the 3.6L and 4.88 gears, I would never recommend 5.13 gears and my God NO! on the 5.38 gears with a 3.6L that is a daily driver and not a dedicated toy/basher. Yea, with 5.13 you get a little better gear on those 10 or 12 days a year that your off-road, but you suffer those gears the 355 days of the year. I went 4.88 gears, and only one time was I feeling like lower gear would be better, and that was at 13,000 feet elevation in Ouray. Often times on the interstates while getting 13.5 mpg I wish that I had gone 4.56 gears!

I agree with the above stating that your Rubi D44 axles are acceptable for overland type work. You may want to consider a weld on axle truss at some point to reinforce the axle tubes that commonly bend/break when abused with 35"/37" tires. But is your really more of a milder trail/overland kind of guy and not getting into the rock crawling, spinning, bouncing beating thing... I think you'll be okay for a lot of years with just keeping up on unit bearing and ball joint swaps. You can head off the ball joints by going with RARE PARTS ball joints once you see your OEM balls are getting sloppy. That just leaves unit bearings that are pretty easy to swap every couple years.

resharp001

I have a 2013. When I slapped on 37" Nittos I still had the factory arms (so axle wasn't moved back). I rubbed pretty bad all the way home from the shop. Had to cut a decent bit off the pinch seam at the front of the rear well.

WaterRat72

Sorry I wasn't a bit more forthcoming with information. It's a 2015 so 3.6 engine with auto trans. Yes a fair bit of freeway driving speeds however most of the time it's just around town.

As for getting offroad, yes it's mostly the fire roads in Death Valley or Anza Borrego with the occasional washed out section or some slight rock climbing. I try to avoid exessive bouncing around. I did Dishpan Spring trail in Big Bear once but that's not really my thing and I tend to stick to more overlanding. It usually doesn't get any worse than what you see in my avatar..

I already cut my rock rails in the rear and the pinch seams in the rear wheel well.

I suppose at a minimum I could tube and gusset the front axle? My next upgrade will definitely be ball joints.

WaterRat72

So bottom line, 4.88's with upgraded ball joints and beef up the front axle? This is good... I was worried about the axles but I guess I'm just being overly cautious.

resharp001

Y, that should do you. Gussets and ball joints at the very least, truss if you can manage it but it might even be overkill. As mentioned earlier, you don't have to have the gears before you slap em on, but the way your jeep drives will get old relatively fast....but the 4.10s will still turn em.

After a couple months of having 37s, you won't think they're very big!