What Are The Largest Tires I Can Safely Run On BUILT Factory D44s?

[rkwfxd]

Hi All,

What is the general consensus or thoughts on running larger tires on BUILT factory D44s? Built as in Artec Truss Front and rear, RCV Axles front and rear, Reid Racing Knuckles, HD Ball Joints or Ball Joint Eliminators, HD TireRod, Ends and Pitman Arm, 5.13:1 Gears but keeping all of the factory fancy shmancy stuff like factory electric lockers, front axle disconnect and swaybar disconnect.

Trails are Big Bear - Holcomb, JB, GM, Cougar Buttes, Shaver / Dusy, Rubicon but in a 21 2 dr with the 2.0T and a light throttle. I don't always need to take the hardest line.

 

[bjm00se]

I pondered the same thing. You can dig up a bunch of threads on this forum and elsewhere, not to mention stuff you'll find on youtube.

The "consensus" answer - which is what you asked for - seems to be 37"

Now, despite that, a number of folks seem to be driving around wheeling the p**s out of their Jeeps on 39" tires.

It's also true that, just as the Jeep can do more than folks tend to expect on stock 33" tires, a capably driven Jeep can also do a lot more than you expect while rolling on 37" tires.

I had a long conversation with my local off-road shop about my usage and my budget, and we landed on 37" tires, even though I'd gone in with the expectation of using 39s.

Your mileage, measured both in mpg, and axle-breaks-per-mile, may vary.

 

[TX_Ovrlnd]

If you don't do the litebrite bounce I am sure you would be fine up to 40s. Is it a daily driven rig? You will hate the MPG, but it is a Jeep so who buys them for that lol.

 

[rkwfxd]

I know a lot of folks are running 37s on bone stock D44s and that of course is still an option.

Im currently on a 2.5" MC GC lift with 315 BFG KM3s. I will for sure go up to 37's on my next tire(s) but the possibility of 39s/40s is kind of / sort of in the back on my mind.

I work from home so while my jeep is technically a DD, I rarely drive it more than 5 miles round trip for errands. MPG on wheeling trips does not matter for me. Especially for long weekends when I flat tow it.

I like to wheel a rig that is a bit over built and more capable than my comfort zone so that I DON'T have issues on the trail.

I ran a TJ on 35s with a locked but stock D30 and bent on axle u-joint ear on one trip one time (but did not realize it until the post trip garage inspection) so overall I think I am fairly easy on my junk.

The JL is just so much more capable and I find myself taking harder lines, I don't want to create mechanical issues for myself (or others in my group) while on a run.

 

[word302]

Here. We. Go.

 

[kah.mun.rah]

My lawyer won’t let me use your term “safely” but if I had that setup I would be running 40s.

 

[sourdough]

I ordered a '19 JLR and flat towed it 30K to trail heads and it was not a daily driver. In the first summer, I found 33's just were not allowing me the comfort zone for clearing obsticles on higher rated trails. After installing a lift and running 37's on trails you mentioned and others, I was much happier. IMHO, 37" is the most tire you need/want on your 2dr. dual propose street/trail rig. Fully mod'd off-roader with 1 ton axles, sure go 40's.
I ran full armor, stock axles with HD steering links and never had a problem. I've always been happy being a spectator of the "send it" kinda guys. I don't mind using my winch or taking a bypass after a failed attempt. I've always babied my rigs and never been a "send it" guy. That's the quickest way to Just Empty Every Pocket. ,even on "built" rigs.
My JLR's OD now shows 21K 90% off-roading miles and I've retired it to D'Ding and F.S. road site seeing. I found the 37's to be too much and I'm on 35's.

 

[MSparks909]

I’d feel comfortable on built D44s with 38s and the 2.0T. The new 38” Nitto’s would be my choice. You *can* run 39s/40s on built D44s but with the 5.13s I’d worry about pinion strength/reliability over the long haul.

 

[Tharris]

I have been running 37s on the stock axels with 4-4 1/2 inch lifted king coilovers and have done many of those listed trails.

 

[word302]

Just realize when you beef everything up on your axle like that, the weak link becomes the ring and pinion. Good luck.

 

[SouthValleyPerformance]

I know a lot of folks are running 37s on bone stock D44s and that of course is still an option.

Im currently on a 2.5" MC GC lift with 315 BFG KM3s. I will for sure go up to 37's on my next tire(s) but the possibility of 39s/40s is kind of / sort of in the back on my mind.

I work from home so while my jeep is technically a DD, I rarely drive it more than 5 miles round trip for errands. MPG on wheeling trips does not matter for me. Especially for long weekends when I flat tow it.

I like to wheel a rig that is a bit over built and more capable than my comfort zone so that I DON'T have issues on the trail.

I ran a TJ on 35s with a locked but stock D30 and bent on axle u-joint ear on one trip one time (but did not realize it until the post trip garage inspection) so overall I think I am fairly easy on my junk.

The JL is just so much more capable and I find myself taking harder lines, I don't want to create mechanical issues for myself (or others in my group) while on a run.

Any concern that if you overbuild it that might tempt you to overdo it?

 

[jessedacri]

You can do all those trails in a JLR on 35s for sure and pretty comfortably too, I've done most of them myself aside from Dusy and the Rubicon but hopefully that changes soon. 37s are IMO as big as I'd realistically go on a 2 door but I think you could likely go 39s "safely" if you drive like you're aware your wheels and tires weigh 140lbs each. IMO 37s give you the "over built" feeling in a 2 door the same way 39-40s do in a 4-door.

I know Tyler thejladventure runs 39s with no trusses and he wheels often but I think he's very skilled on the throttle and wheels with the rig in mind, all things considered. He's always had big setups on basically-stock axles and gotten away with it. The stock axles are strong *except* for the cast FAD housing but with a truss they're tough.

For me I think the gearing and general performance would start to become suboptimal for my tastes beyond 37s. I don't want to run a technically weaker 5.13 ring and pinion, and I know my 4.88s will start feeling undergeared beyond 37, especially with my 3.6. That extra rolling mass adds up fast.

 

[rkwfxd]

Any concern that if you overbuild it that might tempt you to overdo it?

No not really. Good question but I try to be easy on my stuff.

 

[rkwfxd]

You can do all those trails in a JLR on 35s for sure and pretty comfortably too, I've done most of them myself aside from Dusy and the Rubicon but hopefully that changes soon. 37s are IMO as big as I'd realistically go on a 2 door but I think you could likely go 39s "safely" if you drive like you're aware your wheels and tires weigh 140lbs each. IMO 37s give you the "over built" feeling in a 2 door the same way 39-40s do in a 4-door.

I know Tyler thejladventure runs 39s with no trusses and he wheels often but I think he's very skilled on the throttle and wheels with the rig in mind, all things considered. He's always had big setups on basically-stock axles and gotten away with it. The stock axles are strong *except* for the cast FAD housing but with a truss they're tough.

For me I think the gearing and general performance would start to become suboptimal for my tastes beyond 37s. I don't want to run a technically weaker 5.13 ring and pinion, and I know my 4.88s will start feeling undergeared beyond 37, especially with my 3.6. That extra rolling mass adds up fast.

Really great points in your response. Thank you.

I just did a 5 tire rotation and the weight of anything over 37s might be enough to steer me away from them.

37s are prob enough to do any trail I want and as you pointed out, make other things easier/better. 4.88s would be enough AND stronger. Axle upgrades become less urgent as well. Easier to get in and out etc….

 

[rcr1340]

Check out "Rock Ballerina" on YouTube. 5.38 gears, built 44s, 40s. Been running that for 40k miles

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