Ask The Expert- Steps to 37's

[BeachBum]

As you can see from my profile, I have 2017 JK Rubicon Recon (2dr). I installed the 3.5" GC Suspension and am running LT315/70R17 tires (35's at12.50) on stock 4.10 gearing, Dana 44s, 3 pucks on bumpstops (F&R), 2" wheel spacers, When I installed the lift, I used an exhaust spacer from MC and also installed the Rocksport steering stabalizer and mount.. I currently have stock fenders, stock Recon wheels, Teraflex HD tire carrier upgrade. I upgraded my intake/ muffler and have the Pedal Commander to help with acceleration. Everything is working exceptionally well, and I'm a huge believer in MC and the GC suspension. My Recon came with the towing package and normal Recon upgrades.

I've done some searching online, and I can't find an answer to my specific questions so I am asking it here. I hope it's not too redundant from past threads. I love the lift, the 35's, and the wheeling here on Maui is relatively ok with some moderate rock crawing and numerous dirt trails with embedded rock obstacles. Probably the biggest concern is the sharp lava rock that I have to drive over sometimes. I just want bigger tires...

I think that summarizes my current setup. My question is what are the most glaring needs and in order of requirements to upgrade to 37s. I'd like to keep my rims if possible, and since they are working great on the 35's at 12.5 I am hopeful that they won't need to be the first change required (staying with 12.5). My plans are to try and mount the tires, and if they rub the fenders too much (or maybe not at all) I would upgrade to the Mopar High Top Fenders to preserve some of the stock look. I'm wondering what's next. Drive shafts? (both or just one to start and front or back) Big Brakes (the Patagonias I'm looking at actually weigh 3 lbs less - 71 vs 74lbs)? Axle Truss/ Gussets? Gearing (I know I'll probably need that at some point, but where does that fall in importance)? Ball joints (are they super necessary with the Rubicon Recon pkg)? Axles Shafts? Sleeves? Steering box?

I have a little bit of money for some of these things (in addition to the tires) but not enough for all of them. This why I'm asking the question of what is needed, what is absolutely required, and in what order of importance. If 37's will work with no mods, all the better but I'm pretty sure I need at least a front or rear driveshaft (or at least a CV joint kit). Any help wouldbe appreciated. Mahalo!

 

[Cloaked Willys]

Good questions and you have a solid start. Realistically with fenders you will have no issues running 37's with different wheels. The stock wheels are going to be an issue with tire wear on those tires. They call for a 8.5-11" wheel and your stock wheels are only 7.5" wide. the only other thing that you will want to look into sooner than later would be upgrading the gears and possible the axle shafts. The axle tubes are normally pretty good on the Recon. When you are due for brakes look at the Powerstop Z36 kit. They are upgraded pads and rotors that make a big difference.

As with anything some people will need to upgrade more parts than others depending how how they drive and the trails they are running.

 

[ModernJeeper]

We get reports from "old wheelers" who made the same jump in tire size indicating that without exceptional planning and proper modifications, you are reaching the breaking point -- you will start to break junk. You do have a good start with your set up, though, as pointed out by @Cloaked Willys . For your lava rock situation, the key will be tire toughness and sidewall protection. Remember, in rock crawling, the bigger the rim, the less tire exposed; the smaller the rim, the more tire on the rocks. Just get the toughest sidewall you can get.

 

[Macaw1us]

To do it correctly you are going to spend $10,000.00
I did that and then scrapped it all and put a DynaTrac 60 on the front and a Custom 14 Bolt on the rear.
Save the $10 grand and just get the axles and drive shafts first. You are wide open to do what you want after that point.
My street tires are 40" Extreme 2's and my Beadlocks are 39" BF Goodrich Krawlers
With the Extremes I got rid of the rotational pull that comes with the 37" Toyo/Nitto's

 

[Pthorpe84]

As you can see from my profile, I have 2017 JK Rubicon Recon (2dr). I installed the 3.5" GC Suspension and am running LT315/70R17 tires (35's at12.50) on stock 4.10 gearing, Dana 44s, 3 pucks on bumpstops (F&R), 2" wheel spacers, When I installed the lift, I used an exhaust spacer from MC and also installed the Rocksport steering stabalizer and mount.. I currently have stock fenders, stock Recon wheels, Teraflex HD tire carrier upgrade. I upgraded my intake/ muffler and have the Pedal Commander to help with acceleration. Everything is working exceptionally well, and I'm a huge believer in MC and the GC suspension. My Recon came with the towing package and normal Recon upgrades.

I've done some searching online, and I can't find an answer to my specific questions so I am asking it here. I hope it's not too redundant from past threads. I love the lift, the 35's, and the wheeling here on Maui is relatively ok with some moderate rock crawing and numerous dirt trails with embedded rock obstacles. Probably the biggest concern is the sharp lava rock that I have to drive over sometimes. I just want bigger tires...

I think that summarizes my current setup. My question is what are the most glaring needs and in order of requirements to upgrade to 37s. I'd like to keep my rims if possible, and since they are working great on the 35's at 12.5 I am hopeful that they won't need to be the first change required (staying with 12.5). My plans are to try and mount the tires, and if they rub the fenders too much (or maybe not at all) I would upgrade to the Mopar High Top Fenders to preserve some of the stock look. I'm wondering what's next. Drive shafts? (both or just one to start and front or back) Big Brakes (the Patagonias I'm looking at actually weigh 3 lbs less - 71 vs 74lbs)? Axle Truss/ Gussets? Gearing (I know I'll probably need that at some point, but where does that fall in importance)? Ball joints (are they super necessary with the Rubicon Recon pkg)? Axles Shafts? Sleeves? Steering box?

I have a little bit of money for some of these things (in addition to the tires) but not enough for all of them. This why I'm asking the question of what is needed, what is absolutely required, and in what order of importance. If 37's will work with no mods, all the better but I'm pretty sure I need at least a front or rear driveshaft (or at least a CV joint kit). Any help wouldbe appreciated. Mahalo!

I agree with Will on the brake kit. The stock set up struggles at times with 37’s.

I wheeled hard for 4 years with my stock shafts and 37’s and never had a break until this past summer. I was prolly lucky but they do hold up better than most people give them credit for.

I would tell you to start saving for hydro assist. My steering pump finally gave out as well. Lots of stress being put on those components. West Texas Off-Road offers a great economical option for this.

Run the ball joints you have til they go out. It’s a maintenance thing. Sleeves aren’t really worth it but gussets for the C’s are. Drive shafts will eventually give out when flexing at that lift height. Be prepared for that one.

I have ran several different tires, and I can honestly say the Pitbull Rockers have the toughest sidewalls I have seen so far. Super thick and resist being cut on the sharp rocks we have our East. Other tires will perform just fine. But as ModernJeeper said lava rocks are super sharp and can/will cut a tire down. So keep that in mind when picking wheel/tire sizes. I will be doing a write sometime in the spring on Patagonia 42’s as long as they come out in time. They may take top dog on the radial 42” market. We will keep you posted on that one.

On your fenders, you can trim them and still keep somewhat of a stock look. That could save you some money for the time being as well. Good luck my friend.