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

[Chocolate Thunder]

The clear answer is exactly 38. Everyone who says differently is just wrong.

















Or maybe 39. Possibly 40?

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[Fsttanks]

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.

37” tires will easily handle all the trails you mentioned especially on a 2dr. 37s on a 2dr are about equal to 40s on a 4dr when it comes to the majority of the obstacles you will encounter given the dimensional difference between the 2dr and 4dr.

I run all the trails in BB running 35s on a 4dr and have no issues.

 

[rkwfxd]

Tons of good information and insight here. Thank you very much.

 

[Zandcwhite]

38's (milestar Patagonias on factory wheels so light 38's) on stock 44's and 5.38 gears on all those same trails without an issue. Even the factory ball joints made it to 40k miles. HD replacements went in then. If you want to bounce it you need bigger axles. If you wheel it like a $50k+ that you want to keep looking new from the sliders up and you'd be good up to 40's with rcv's and a truss.

 

[Roky]

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.

I have no idea how big you can safely go because I have no idea how you use it. How you use it is the determining factor.

Me personally……I’m not gonna run anything bigger than 38s. By then I’ll be on the factory 44s with RCV front axle shafts, rear Yukon shafts, trusses and 4.88 gears. Right now I’m on 37s and it has done everything I’ve asked of it without issue…….

 

[Zandcwhite]

RCV's, HD ball joints, rear gear, truss, big brake kit, spare tire carrier and labor = 1 ton upgrade IMO. On OP's 2 dr. dual purpose rig , 35's, stock axles and some armor are all that's needed.

Not sure how a spare tire carrier factors in, if I go to tons do I no longer need to carry a spare? I agree with the idea of your post, to a point. If you were going full build out the gate and buying all those parts and doing none of the work yourself you’d be about 70% of the way to the cost of tons, although odds are if you can’t install a set of shafts you probably aren’t the type to wrestle a 5-600lb front axle under your rig either. With the tons you also need wheels, likely brake lines, new steering, maybe new track bars depending on how the mounts are set up and what you are currently running. The budget to realistically put tons under your rig is going to be pushing $20k, a far cry from shafts and ball joints, and a regear the only things you really need to run 39-40’s in my opinion. With gears and ball joints I’m under $3k in to my axles and the splines looked good as new after 3 years when the gears went in in March. Could I break a shaft at any moment? Absolutely. Will I go rcv’s or tons if I do? Depends on my mood when I get to that point I guess. For now I’d say I’ve more than gotten my money’s worth out of the stock axles wheeling all over the country.

 

[rkwfxd]

RCV's, HD ball joints, rear gear, truss, big brake kit, spare tire carrier and labor = 1 ton upgrade IMO. On OP's 2 dr. dual purpose rig , 35's, stock axles and some armor are all that's needed.

I respect your opinion and Im already there. While the 315s are a tad small Im on 2.5” lift, full armor and a tire carrier.

Axle upgrades and 37s would be the next step but everyone is kind of talking me out of it.

 

[limeade]

I'd be more worried about the weight of the tire/wheel combo than the overall diameter. A lightweight 38" or 40" tire/wheel combo would be easier on the drivetrain than a heavy 37" combo (assuming you drove the same way with each combo).

I've done all of the upgrades you are looking at (except for the truss, which is on my list), but have 4.88's. I run a fairly light wheel (Vision Nemesis at 26lbs each), tires are 79 lbs, but I use just enough throttle while in the rocks. I'm fairly confident with the durability of my axles at this point, with the weak link being the FAD housing. For now, I'm very conscious of not coming down hard on the front axle.

One thing to consider when moving to 1 ton axles is the increase in weight from the larger axles. Yes, they're stronger, but your Jeep will be heavier. Not a deal breaker, but should be mindful of the increased weight.

 

[Zandcwhite]

You made my point. Your 44's will never be up to task of handling tires bigger than 37's gingerly wheeled. "got my moneys worth out of the stock axles" ? What stock axles, you listed upgrades. Drip, drip, drip money down the drain. You don't see serious built rock crawlers on D44 for a reason. They won't/don't last and after all the money, you'll still need tons for any thing but mall crawling.
Rubicons with factory warranties are limited to a light 35" tire option also for a reason.

The stock ball joints made it 40k miles, on 37's. The gears got swapped out 3 months ago at 55k miles and that definitely wasn't a strength upgrade? Bone stock axles on 37's did moab twice (steel bender, metal masher, cliffhanger, top of the world, poison spider through gold bar, kane creek, behind the rocks, hells revenge including held Hell's gate), the dusy erishim trail, John Bull, Holcomb creek, gold mountain, multiple trails around tillamook, multiple trails in telluride, multiple desert trails in NV, UT, and AZ including freeway speeds in the dirt and a bit of air time. No it hasn't been wheeled gingerly but it hasn't been driven like a rock bouncer either. Since the ball joints and gears it's been roadtripped across the entire country and run trails in AL, AR, NV, AZ, CA, and UT including gutbuster at stoney lonesome which was the toughest badge trail I've run and one that everyone including the park owners said only the rock bouncers run these days. All on 38's. If you wheel smart, stay out of the throttle when bound up or at full lock, and don't bounce it your stock axles can handle 37/38's easily. If they can warranty 35's with a 392 spinning them, us lowly 2.0t or v6 owners should be safe on 40’s...

And I’d hardly call it money down the drain, this thing has taken us to and through some of the most amazing places this country has to offer for 60k miles now. Money well spent for sure.

 

[X99104]

The clear answer is exactly 38. Everyone who says differently is just wrong.





Or maybe 39. Possibly 40?

Come on now we all know the answer to life, the universe and everything is 42

Seriously I ran a set of Nitto Ridge Grapplers on my 19 JLUR stock axles for almost 60K miles before trading it in. Alot of highway but take it for what its worth

 

[J0E]

I'd be more worried about the weight of the tire/wheel combo than the overall diameter. A lightweight 38" or 40" tire/wheel combo would be easier on the drivetrain than a heavy 37" combo (assuming you drove the same way with each combo).

That's the opposite of the physics. Torque = Radius Cross Force. It's the wheel diameter. The weight difference of even heavy beadlocks and heavy tires is inconsequential compared to the lifting the mass of the vehicle. Don't even think about bumping it. If you were going in the snow and crawling, you could run the most massive 46s with no problem, in snow you wouldn't be able to climb steep obstacles.

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

And going deep on the ratio to compensate for big tires makes that weaker.

How Big of Tires Can You Run on a Dana 44? From an axle repair shop.
deeper you go in ring/pinion ratio, creates a weak point.
D44 on 33 robust
Axle repair expert puts it at 37

 

[c20040215]

 

[J0E]

Here he says D44 up to 37" tires unless you hit the hardest trails and have 4 people in the rig.

He gets power confused with torque because he's never taken physics. My axle expert makes the same mistake.

 

[Zandcwhite]

Obviously for 40"+ tires, 1 tons are the safe bet. That doesn't mean you can't run 40's on a d44 it just means failure is more likely. I take experts advise with a grain of salt as they are typically in the business of selling parts/upgrades (should I recommend $1k axle shafts or a $10k axle...) or they own fab shops where their 1 ton junk yard swap costs then slightly more than a set of shafts, or they run a sponsored rig and cost means nothing. Will I ever run larger than the 38's on the Jeep? Not sure. Will a 1 ton swap happen? Depends on if issues with the d44's arise.

 

[Roky]

@rkwfxd I personally think that 2 doors look and perform the best on 2.5” lift and 37s. You can still get plenty of articulation with clearancing your fenders or going aftermarket. Or tuning with bump stops. But I’d rather tune bumps to maximize uptavel of the shock as opposed to worrying about fenders….in other words, you’ll have better articulation and nimbleness than if you went to 39-40s without increasing lift height. To me that’s better than the 1.5-2” diff clearance you’ll get…….

At 2.5” it keeps the rear driveshaft at a decent angle….. also doing everything to your axles you mentioned will definitely help.

But common sense out wheeling is your best mod….. better than all the upgrades put together. If it was me, I wouldn’t go any bigger than 37s……….just somecents…….

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