2021 40” Rubicon Diesel Build

[guarnibl]

Spoken like someone who knows exactly what they are talking about.

I was thinking the same thing, do it right one time the first time. I do not want to play the break it and upgrade game.

Also doing it right the first time is cheaper in the long run. I’ve done the math on putting this thing on 37” tires basically stock and slowly upgrading to the 40”.

Its quite a waste of money to do it that way if it’s not what you want. By my numbers I would’ve wasted about $6k not including an axle swap if I went that route.

So now I am back to doing the axle swap upfront. Which totally changes a lot of stuff on my build sheet lol

Been doing it 10 years (lots of folks here probably been doing it far longer than me). For the first 5-6 years I was always saying... this year will be cheaper. Good laugh that was. But yeah, I'd prioritize axles armor recovery first.

For axles, get a little wider than stock so you're not worried about backspacing, but not too wide that you're struggling to fit through trails.

You'd probably be fine with a 60 rear but given the price differential if it were me and I'm doing it today... I would literally just buy the Dynatrac XD60/80 combo and call it a day. No doubt as others have mentioned, there's ways to do it cheaper -- but -- for ~$5-$6k more, it's the 'easy button.'

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[40”JLURD]

Save the money on the rear and just throw a 14B in there. You can literally pick them up for $125 with factory discs...then throw in your locker and gears.

Well, don't forget...those housing prices are JUST housings. You still have to buy inner Cs and knuckles as well as steering arms.

Solid Axle, Reid Racing, Artec (arms...as an example), Crane, Spidertrax, etc. all make knuckle/arm assemblies and most have inner Cs as well. That stuff will not be cheap....figure $2K at least. Spidertrax's are probably the best...but they are even more money.

Yes, you're going to need brakes, spindles, bearings, lugs, etc. You can go simple like 3/4T Chevy single piston calipers, Ford 2 pistons or go $$$ and get the Wilwood conversions.

Personally, I'd recommend a kingpin knuckle and tapered roller bearing set up over ball joints and unit bearings, but some of those companies don't give you the option (for example, Spidertrax uses a "kingpin" style knuckle but you have to use unit bearings...which is a great combo...just expensive).

Save the money on the rear and just throw a 14B in there. You can literally pick them up for $125 with factory discs...then throw in your locker and gears.

Well, don't forget...those housing prices are JUST housings. You still have to buy inner Cs and knuckles as well as steering arms.

Solid Axle, Reid Racing, Artec (arms...as an example), Crane, Spidertrax, etc. all make knuckle/arm assemblies and most have inner Cs as well. That stuff will not be cheap....figure $2K at least. Spidertrax's are probably the best...but they are even more money.

Yes, you're going to need brakes, spindles, bearings, lugs, etc. You can go simple like 3/4T Chevy single piston calipers, Ford 2 pistons or go $$$ and get the Wilwood conversions.

Personally, I'd recommend a kingpin knuckle and tapered roller bearing set up over ball joints and unit bearings, but some of those companies don't give you the option (for example, Spidertrax uses a "kingpin" style knuckle but you have to use unit bearings...which is a great combo...just expensive).

The rear sounds easy enough, I’ll have to do some research on those about what widths they come in and in what vehicles etc. That can be done pretty easily and sounds like it will save a ton on the axle swap.

The front though... I think building one from scratch may be a little hard for me, it’s slightly above my skill level. One of the other pre built units would be way easier. And cheaper it sounds like... Alrhough I really like the looks of those housing and third members I personally would not probably be able to order all the stuff to build one from scratch and get it all right.

 

[guarnibl]

The rear sounds easy enough, I’ll have to do some research on those about what widths they come in and in what vehicles etc. That can be done pretty easily and sounds like it will save a ton on the axle swap.

The front though... I think building one from scratch may be a little hard for me, it’s slightly above my skill level. One of the other pre built units would be way easier. And cheaper it sounds like... Alrhough I really like the looks of those housing and third members I personally would not probably be able to order all the stuff to build one from scratch and get it all right.

I'm one of those in the camps that mods don't really add value to a Jeep -- but I can tell you resale of your $50k+ Jeep will be significantly better with a known manufacturer under there instead of a junk yard axle. Enough so that I'd argue it actually saves you money. Up front junk yard axle is materially cheaper though, but it will require a lot of effort if you're into that.

Look at the full ownership landscape and not just a single part is my advice there.

 

[40”JLURD]

No to the KM3.

It's not just the weight...it's the leverage. I seriously doubt the Yoko is actually a true 40" tire either though. Tire mfgs are allowed to vary their size by +/- 10%. On a 40, that's a full 8" either way (though I don't know of any tire makers that go that far out of spec...and it's extremely rare they go larger at all).

Yokohama claims 39.7” in their specs

 

[40”JLURD]

I'm one of those in the camps that mods don't really add value to a Jeep -- but I can tell you resale of your $50k+ Jeep will be significantly better with a known manufacturer under there instead of a junk yard axle. Enough so that I'd argue it actually saves you money.

Look at the full ownership landscape and not just a single part is my advice there.

This is also a negative for sure. I also don’t like the junkyard axle in what is now absolutely 100% a OVER $100k Jeep

 

[40”JLURD]

OP,

You never answered why you're even bothering with a Rubicon in the first place. The factory 4:1 tcase isn't all that strong.

I was under the impression that was THE ONE to get. Plus the t case at 4:1 would be good in my opinion but I know nothing of it’s strength. (Be it good or bad?) I’ve been out of the wheeling game about 15 years now. So learning a lot of new stuff quickly

 

[40”JLURD]

OP,

You never answered why you're even bothering with a Rubicon in the first place. The factory 4:1 tcase isn't all that strong.

Here’s a better answer. I just compared the sport and you can’t get leather seats, the 8.4” screen or a shitload of other options that I ordered. So even if I chop off the whole driveline (and then sell most of it) I would want the Rubicon package

 

[40”JLURD]

This set of Dynatrac is look more and more appealing.... except the price. But that aside I like... After selling my stock Rubi axles I’ll only be out about $6k more than beefing up the stock axles


The Hard Core Plus™ ProRock XD60®/XD60 Axle Set is for Jeep Wrangler JL owners running tires up to 40-inches in diameter who do not want to be limited to what trials or challenges they encounter.

WHAT YOU GET:
PROROCK XD60® FRONT AXLE

• Dynatrac exclusive patented ProRock® nodular-iron, high-pinion ProRock XD60® centersection with bearing bores to handle oversize pinion and carrier bearings for elite housing rigidity.
• More ground clearance than any other axle housing in its class.
• 3.75-inch diameter, variable wall thickness, lightweight, chromoly tubing has the highest strength-to-weight ratio compared to any other light-truck axle on the market.
• Dynatrac exclusive Dual-Sump High Volume™ (DSHV) oiling system to ensure the outer pinion bearing is never without lubrication.
• Dynatrac-exclusive U.S.-made forged, double-heat-treated 1550 35-spline axleshaft assemblies. These are the best shafts in the industry and are capable of up to 50-degree turning angles.
• Our new 1550 LT® high-strength, lightweight, military-grade, aluminum knuckles are loaded with our best set of Dynatrac HD BallJoints™ yet. These are the last balljoints you’ll ever need, and are designed with larger stems and bodies for long life and high durability with big tires.
• Forged 4140, heat-treated, fixed spindles and serviceable wheel bearings support tires up to 44 inches.
• No other 4x4 front axle offers the ease of steering, lowscrub radius, effective Ackermann angle and high steering linkage positioning.
• Includes Dynatrac high capacity 13.25-inch brake upgrade with new dual-piston front calipers and vented rotors.
• Includes our latest integrated track bar and ram-assist steering mounting package.
• Includes new HD tie rod, integral steering arm, control arm bushings, CNC laser-cut HD suspension brackets, all professionally welded and installed.
• Includes DynaLoc™ locking hubs. DynaLoc hubs are over 3 times stronger than all other locking hubs on the market.
• Available in standard 68.5 inch width or 72.5 inch Wide Track.
• Comes with an ARB Air Locker, Eaton ELocker4 or Auburn Gear EXTED MAX locker, and your choice of 4.88, 5,13 or 5.38 gears.

NOTE: Comes with 35-spline shafts, hubs and locker.

PROROCK XD60® STANDARD-CUT FULL-FLOAT REAR AXLE

• The strongest 60-series rear axle available – PERIOD!
• Exclusive XD60 rear housing with ProRock ground clearance
• Low-pinion, standard-cut gearing for ideal rear-axle application
• Increased pumpkin rigidity – better stability in gear mesh for higher durability under extreme loads
• Better strength, better gear stability
• High-capacity carrier-bearing saddle structure
• 7/16-inch cover bolts – cover now adds additional structure to the housing
• O-ring cover seal and hard contact mating surfaces
• Best ground clearance – No ribs underneath
• Industry leading 4-inch axle tubes
• Best strength-to-weight ratio
• Available in standard 68.5 inch width or 72.5 inch Wide Track.
• Comes with an ARB Air Locker, Eaton ELocker4, Auburn Gear EXTED MAX locker and your choice of 4.88, 5,13 or 5.38 gears.

 

[40”JLURD]

Meh...balljoints in aluminum knuckles and axle shafts that don't rival RCVs and hubs that are not stronger than slugs and several things that are debatable....sounds like marketing hype.

Then help me put together a complete parts list for a better front! Please and thank you!!

 

[40”JLURD]

I don't think you understand the can of worms you're opening if you build one.

For you...it's probably easier to just buy a complete axle assembly with lockers/gears already in them.

Agreed

How about these?

Currie Extreme 60 - High-Pinion Jeep JL Axle Set (70 In. Wide, 8-Lug)

• Currie Extreme 60 - High-Pinion Jeep JL Axle Set (70 In. Wide, 8-Lug)

• 1
• 2

The Currie Extreme 60 front and rear axle set for the Jeep Wrangler JL, is designed for severe off-road use with tires up to 40-inches and V8 horsepower. The high-pinion design features Currie's exclusive rotated center section with ring gear load-bolt, a combination that delivers superior obstacle slide-over and unmatched gear strength. If you seek out the most challenging routes and toughest obstacles to conquer, the Extreme 60 axle set is a natural choice.
Axle Set Details:

• Fully Assembled Extreme 60 High-Pinion Front And Rear Axle Assemblies
• 70-Inch Width Provides Improved Clearance For Large Tires
• 8-Lug Wheel Bolt Pattern For Ultimate Reliability
• Satin Black Powder Coat Finish For Long Lasting Protection
• Choice Of Selectable Locker And Gear Ratio

Exclusive Extreme 60 Features:

• High-Clearance Center Section With Rotated Cover Improves Obstacle Slide-Over
• High-Pinion Design Raises The Driveshaft By 2-Inches For Additional Clearance
• Ring Gear Load Bolt Prevents Deflection To Deliver Maximum High-Pinion Gear Strength
• High Volume Flow-Thru Pinion Oiling System Keeps Bearings Bathed In Cool Oil
• Rock Slider Low-Friction Skid Plate Sides Over Trail Obstacles With Ease

 

[40”JLURD]

Same issues....great bolt on option. But for less money, you can build a custom axle that's stronger....but you have to do a lot more work. Hell, you can go to Crane or Reid to get their larger than D60 inner Cs and run 2" 40 spline shafts with enormous ujoints....but that's going to send the cost to another level even higher.

One big advantage of building yourself is getting the caster angle in relation to the pinion angle you actually need b/c you're the one setting the caster before you weld the inner C to the housing (obviously your builder would do that)....but if you don't know your projected ride height as well as the pinion angle necessary to mate to the tcase and front driveshaft (double cardan or flanged yoke ujoint for example) you've chosen, buying a complete axle housing from Dynatrac or Currie (or even Spidertrax) is going to net you something that may not be optimal in terms of driveline angle and caster.

I’m going with an EVO Coilover Kit which requires cutting off most of the brackets on the axle and welding on new ones.

Wouldn’t that take care of any generic fitment issues?

 

[40”JLURD]

I’m going with an EVO Coilover Kit which requires cutting off most of the brackets on the axle and welding on new ones.

Wouldn’t that take care of any generic fitment issues?

Another thing: what is your "builder" actually building? Is he going to make a custom linked suspension with coilovers/bypasses or is he just bolting on some short arm or long arm lift kit?

Most of the stuff Dynatrac/Currie are hawking is set up to bolt into a factory Jeep in terms of the link mounts. Personally, that geometry is pretty shitty....and could be made a lot better if someone took the time to build the suspension themselves. That means you wouldn't need all the mounts and should save you some money from Dynatrac/Currie.

its the Evo Pro Long Arm Coilover Kit to be exact. Which requires a lot of cutting and welding and positioning things on the Jeep then welding in place. It’s a 40 hour install “to set it all up correctly” . That’s what I was quoted from him

 

[ChattVol]

I don't think you understand the can of worms you're opening if you build one.

For you...it's probably easier to just buy a complete axle assembly with lockers/gears already in them.

I'm confused...you suggested it would be better for him to buy a complete axle assembly with lockers & gears. He's suggested Dynatrac or Currie...you found flaws with both and didn't seem to recommend either. In your opinion, what is the best complete axle assembly with lockers & gears that would semi meet his hypothetical needs?

 

[guarnibl]

Trying to sell a built, wheeled Jeep for a profit is a losing proposition. You likely won't even come close to recouping your investment. Hell, for the most part, vehicles are not investments....especially something that sees rigorous offroad use.

Just so we're clear, I never suggested that.

My post was suggesting that :

1) It is easier to sell an expensive vehicle with modifications when the modifications (especially part of the drive train) come from a reputable source. I.e., Dynatrac/Currie/Dana. This also holds true in the high end luxury car market.

2) Adding onto point #1 -- that you will also be able to sell the vehicle for more money, holding all other things constant.

With anything related to vehicles/toys -- the quickest way to get to a million is start with two. If the OP puts $100k into the Wrangler, it will probably be worth $30-$50k five years down the road assuming maintained properly. Also, race car parts cost race car money and require race car maintenance. =)

 

[guarnibl]

I'm confused...you suggested it would be better for him to buy a complete axle assembly with lockers & gears. He's suggested Dynatrac or Currie...you found flaws with both and didn't seem to recommend either. In your opinion, what is the best complete axle assembly with lockers & gears that would semi meet his hypothetical needs?

No he's saying that there are trade offs you make when buying off the shelf vs building your own, but for the OP, he's likely better off from an experience perspective to go the off the shelf route. I agree.

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