Questions/Options for JLR 38" Build

[Testingthewaters]

Would appreciate some feedback and input before I drop a chunk of change. Working toward 38x12.5 Nittos on 17x9, -12 wheels (4.5 backspace).

2019 JLR 2.0T with 60k miles. 2.5 Gamechanger lift with HD Steering (extra height, without spare or back seat), Sector Brace and Dynatrac Ball Joints. Both driveshafts are upgraded.

Worked with a shop on the suspension and steering that's recommending:

5.13 Gears
RCV Front Axle, Chromoly Rear
Truss Front Axle Only (Artec Full Armor)

Another estimate from a well-regarded shop only recommends:

5.13 Gears
Reid Knuckles (and new ball joints)

Wanting to think through what's necessary. I don't wheel hard, and it's a daily driver, but I live in the Rocky Mountains and am daily on mountain passes, forest roads, etc. and want reliability more than rock crawling potential. Not opposed to paying to over-build, but wondering how far I might get with the stock axles (or parts thereof). Where are the weak points? Other comments on drivetrain, brakes, etc. are welcome.

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[chevymitchell]

Would appreciate some feedback and input before I drop a chunk of change. Working toward 38x12.5 Nittos on 17x9, -12 wheels (4.5 backspace).

2019 JLR 2.0T with 60k miles. 2.5 Gamechanger lift with HD Steering (extra height, without spare or back seat), Sector Brace and Dynatrac Ball Joints. Both driveshafts are upgraded.

Worked with a shop on the suspension and steering that's recommending:

5.13 Gears
RCV Front Axle, Chromoly Rear
Truss Front Axle Only (Artec Full Armor)

Another estimate from a well-regarded shop only recommends:

5.13 Gears
Reid Knuckles (and new ball joints)

Wanting to think through what's necessary. I don't wheel hard, and it's a daily driver, but I live in the Rocky Mountains and am daily on mountain passes, forest roads, etc. and want reliability more than rock crawling potential. Not opposed to paying to over-build, but wondering how far I might get with the stock axles (or parts thereof). Where are the weak points? Other comments on drivetrain, brakes, etc. are welcome.

The right answer is that the Dana 44 is too small for a 38”+ tire. Everything after that is just moving the weak link. If your intention is to not go with 60’s, then you’re on the right track. Chromoly’s shafts, ball joints, and a regear. That will get you down the road great. I wouldn’t spend any more money than that on those axles. Save your pennies for a UD60 or a ProRock44 at a minimum.

 

[kah.mun.rah]

For the front axle, add up the cost of the truss, re-gear, axle shafts, knuckles, HD diff cover, ball joints along with what you could sell your stock axle for and you will probably be around what a Dynatrac ProRock 44 or an Ulimate Dana 60 would cost.
Edit: what Shawn said above...haha

 

[grimmjeeper]

I spent the money to truss my axles and upgrade the shafts, along with Reid knuckles and upgraded ball joints up front. Two reasons:

1. I can do all my own work, including welding. This kept costs down as I only needed to pay for parts.

2. I am stopping at 37s. Any bigger and I would have looked at aftermarket axles.

I agree with everyone else. Paying a shop to upgrade your axles is money you can spend on aftermarket axles. It may not be 100% of the cost to upgrade but aftermarket axles are stronger than reinforced factory axles and a better deal in the long run for 38"+ tires.

 

[Testingthewaters]

Thanks, all. This is super helpful. The logistics of a full axle swap (though admittedly the best option) would be difficult for me to manage, including the sale of the old axles.

No question on the necessity of the gears (I'm currently 4.10 with 37" K02, and unhappy). And the only downside of the full build (truss, shafts, knuckles, ball joints, etc.) is financial - all would provide some measure of protectiogen.

Would consider an AT 37" (need snow/ice traction), but feel like the conversation on axle build would be similar to the 38" - no interest in larger tires without an axle swap.

Really just wanting to poll the experts on possibly skipping out on truss, knuckles and or shafts. Some input from folks without the self-interest of sales/commission...

 

[kah.mun.rah]

It may not be 100% of the cost to upgrade but aftermarket axles are stronger than reinforced factory axles and a better deal in the long run for 38"+ tires.

And it's a chance to get rid of the weak link (the FAD) and correct me if I am wrong, but I believe that the aftermarket axles have the control arm brackets in positions for better caster angle with a lift.

 

[Camaroboi13]

Yeah, put the tires and gears on and enjoy the rig. Replace the ball joints when they wear out. 44s will hold those tires just fine.

 

[kah.mun.rah]

possibly skipping out on truss, knuckles and or shafts. Some input from folks without the self-interest of sales/commission...

I stay away from chromoly shafts because if in a bind on the trail, I would rather my axle shaft take the break than a ring gear tooth. Cast knuckles are better than the stock aluminum, but depending on how you abuse it, I am not sure if cast are a "must have" with daily driving 38s. The ball joints, yes, it is just a matter of time before replacing those with larger tires.

 

[grimmjeeper]

Thanks, all. This is super helpful. The logistics of a full axle swap (though admittedly the best option) would be difficult for me to manage, including the sale of the old axles.

No question on the necessity of the gears (I'm currently 4.10 with 37" K02, and unhappy). And the only downside of the full build (truss, shafts, knuckles, ball joints, etc.) is financial - all would provide some measure of protectiogen.

Would consider an AT 37" (need snow/ice traction), but feel like the conversation on axle build would be similar to the 38" - no interest in larger tires without an axle swap.

Really just wanting to poll the experts on possibly skipping out on truss, knuckles and or shafts. Some input from folks without the self-interest of sales/commission...

I would absolutely do a truss and gussets on a stock axle for any 37" or bigger tires. It band-aids most of the weak points of the factory axle (FAD, diff housing, inner C's).

 

[grimmjeeper]

And it's a chance to get rid of the weak link (the FAD) and correct me if I am wrong, but I believe that the aftermarket axles have the control arm brackets in positions for better caster angle with a lift.

Some aftermarket companies do various things to accommodate lift. They usually keep the brackets in line with the inner Cs but they clock the differential to point the pinion up a bit to help reduce vibrations.

 

[Remorseless]

Would appreciate some feedback and input before I drop a chunk of change. Working toward 38x12.5 Nittos on 17x9, -12 wheels (4.5 backspace).

2019 JLR 2.0T with 60k miles. 2.5 Gamechanger lift with HD Steering (extra height, without spare or back seat), Sector Brace and Dynatrac Ball Joints. Both driveshafts are upgraded.

Worked with a shop on the suspension and steering that's recommending:

5.13 Gears
RCV Front Axle, Chromoly Rear
Truss Front Axle Only (Artec Full Armor)

Another estimate from a well-regarded shop only recommends:

5.13 Gears
Reid Knuckles (and new ball joints)

Wanting to think through what's necessary. I don't wheel hard, and it's a daily driver, but I live in the Rocky Mountains and am daily on mountain passes, forest roads, etc. and want reliability more than rock crawling potential. Not opposed to paying to over-build, but wondering how far I might get with the stock axles (or parts thereof). Where are the weak points? Other comments on drivetrain, brakes, etc. are welcome.

The ball joints are almost mandatory even for stock size tires, the OE units wear out quick, so that's a good recommendation IMO - one I'd keep. Knuckles aren't a bad idea, the aluminum OE ones can snap (usually takes driving like a goober though).

I go against the grain for trussing though - plenty of folks have run 37s or 38s on JK D30s and JK D44s for years without trussing (the folks running 37s and 38s on JK D30s are braver than I am though...). If you're really beating on the Jeep a truss or a D60 is a good idea, but honestly, not necessary for most folks who wheel carefully. Wheel reasonably (it's a Jeep, not a trophy truck or a SxS) and some 38x12.50s will do fine without a truss, particularly given that the JL iteration of the 44 is stronger than the JK's (thicker, larger diameter tubes, larger diameter shafts).

For gears, I'm in the camp of 4.10s + 37s is fine with the 2.0T, but 5.13 with the 2.0's torque is a little short for my tastes. 4.56 or 4.88 would be my thoughts there, but I tend to usually run light on gearing preferences, so YMMV.

 

[c20040215]

D44 can handle 37s/38s just fine with some upgrades and smart decision making on the trail.
I would not spend big money on a D44s thinking I can reliably run 40s.

I did the front and rear truss and C gussets while doing the regear. That saved me a few bucks.
Upgraded the rear shafts to chromoly after I bent the OE shaft flange. And the ball joints were upgraded as well. All the cost were spread out. This is one thing that rarely talked about. All the upgrades you can do to your D44 can be done gradually. Sure D60s are much stronger and you can offset costs by selling your D44, but it is still a one time, 5 digit investment no matter how you slice it.

I personally would not lose sleep over 37s/38s on D44.

 

[Remorseless]

D44 can handle 37s/38s just fine with some upgrades and smart decision making on the trail.
I would not spend big money on a D44s thinking I can reliably run 40s.

I did the front and rear truss and C gussets while doing the regear. That saved me a few bucks.
Upgraded the rear shafts to chromoly after I bent the OE shaft flange. And the ball joints were upgraded as well. All the cost were spread out. This is one thing that rarely talked about. All the upgrades you can do to your D44 can be done gradually. Sure D60s are much stronger and you can offset costs by selling your D44, but it is still a one time, 5 digit investment no matter how you slice it.

I personally would not lose sleep over 37s/38s on D44.

Something that folks also rarely talk about is that, unless you go to a much larger tire, you lose clearance with a D60 vs a D44. The housing and tubes being larger on a D60 do add strength, but they do lower under-axle clearance. If you go from 37s on a D44 to 38s on a D60, you've lost a solid 1-1.5" of clearance, if not more. For that tire size and weight, I'd rather have the clearance of the 44 and hit my axles on stuff less.

 

[c20040215]

Something that folks also rarely talk about is that, unless you go to a much larger tire, you lose clearance with a D60 vs a D44. The housing and tubes being larger on a D60 do add strength, but they do lower under-axle clearance. If you go from 37s on a D44 to 38s on a D60, you've lost a solid 1-1.5" of clearance, if not more. For that tire size and weight, I'd rather have the clearance of the 44 and hit my axles on stuff less.

I agree. That crossed my mind when I typed my post. I guess if you have 37s on D60s, you can use some wheel speed to just plow through whatever its in your way lol

 

[Remorseless]

I agree. That crossed my mind when I typed my post. I guess if you have 37s on D60s, you can use some wheel speed to just plow through whatever its in your way lol

I've seen folks in JKs bend the tubes on D60s doing that lol. They were on 40s and the rocks weren't small, but a built Jeep with some oomph behind her will fuck up all kinds of axles lol

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