Jk44s in an MJ?

[Dirteatr717]

If you guys had a line on a set of JK 44s front and rear, that came with 4.10s and lockers would you stick em under your MJ? Of course you would have to redo all the axle brackets and maybe re-gear them but since they are a little wider and many people run 37s on them which I want to do. Would it be worth the work or should I not even bother Thinking about them and just build a HP44 and a D60?

:idea: :dunno: -Nick

[Motion Offroad]

They are aprox 5" wider WMS than the XJ/MJ axles are. Bolt pattern is different so you'll have to run new rims, or use a set of wheel adapters.

 

The JK D44 is stronger than the factory D30 but it still has it's issues. Their is a reason all the JK guy are yanking them out and putting D60's upfront.

 

Honestly it depends on the price of the D44's.

 

Here is a photo of a JK D44 in a XJ.

 

[Dirteatr717]

Exactly what I was looking for, thank you! I know I'd have to get new rims and a JK trackbar and Ive seen many people swap out the 44 for a 60 but I feel like it's the same debate most of us with XJs and MJs have with d30s and 35s, I know eventually I'll want to go bigger so I'm just going to skip that step and go right to 37s and I'm not a hardcore wheeler, I like to pick my lines out carefully and go slow so I feel like with my driving style and 37s I think a JK D44 would hold up just fine. I'm just starting my research but thanks again!

-Nick

[Sir Sam]

I'm doing this in my MJ, well the front at least.

 

The rear is easy, just cut off the existing brackets and weld in some new ones.

 

The front is harder. As previously stated its wider and its a 5x5 bolt pattern. Personally I am going to get the hubs redrilled to 5x4.5 so I can run my silverstar wheels. (And then I can redrill rotors myself since they are hub centric and a little variation in the bolt pattern on the rotors is OK.

 

If you are running aftermarket control arms with johnny joints then you ought not to need to move the brackets. I've been through all this before but my conclusion was that I would be fine leaving the brackets where they were. IIRC the lower control arm brackets are 1" further apart than a stock XJ/MJ/TJ/ZJ, which means each side is .5" further apart. I remember the uppers being the same......hmm, I might need to get the axle back out and remeasure these things.

 

The coil buckets, shock mounts, etc, are all different on the JK axle. You can cutoff the JK coil buckets(which are too wide anyways) and toss them, then from a donor axle cutoff the XJ coil buckets, which include the shock mounts and swaybar links, and weld them to the JK axle. Thats my plan at least.

 

The JK axle does seem to have some kinda weak tubes, so if you are gonna be running big tires on it or wheeling it a lot I would recommend either trussing it or using the internal reinforcing kit. I forget who but some company makes a kit where you can insert a tube in the axle tube complete with new seals, to reinforce it without an external truss.

[Dirteatr717]

Awesome info, I have Clayton y-link longarms with bushings on the axle end. I planned on using TNTs truss and if I can find a donor axle I'll do as you said and use the old coil-shock mounts, I do plan on running 37s but I'm not going to be rock racing haha :no:

[Sir Sam]

Awesome info, I have Clayton y-link longarms with bushings on the axle end. I planned on using TNTs truss and if I can find a donor axle I'll do as you said and use the old coil-shock mounts, I do plan on running 37s but I'm not going to be rock racing haha :no:

 

 

I took a bunch of comparison photos too between the XJ dana 30 and the JK D44 and I'm wondering what happened to those......

 

I just rechecked the measurements, the upper control arm mounts on the JK axle measure 1" wider than the XJ axle. The Lower control arm mounts measure the same width.

 

So each upper arm needs to be able to mount .5" further apart than stock on the axle.....hell I think there is that much extra play in the stock arms.

[Sir Sam]

This it what the JK coil buckets and stuff looks like:

 

and an XJ:

 

so very different, and like I said earlier the coil buckets are just too wide, so since they need to be rewelded further in, you might as well just use XJ buckets so everything will just boltup.

 

IMO not a bad conversion.....oh and JK uses a CV style input too, not a yolk.....not sure what to say about that.

[xjrev10]

How much more weight is a JK over a MJ? I would guess quite a bit.

 

If you where to take the JK axles, build them like the JK guys do that keep the 44s, I don't think they would have any trouble standing up to 120HP and 37s. But in all honesty I'm thinking out loud. I'm currently looking for unique or different options in the axle department for my next project besides doing a D60 to run 37s. Lots of weight to contend with there.

 

Also you would be keeping pure jeep.

[Dirteatr717]

Currently my truck weighs 3,700 #s with me in it, a stock 2dr Rubicon JK weighs ~ 5,000 #s that's a pretty big difference!

Also wouldn't you have closer to an inch more ground clearance with d44s and 37" tires than with a d60 and 37"s?

[H8PVMT]

I thought the jk front 44's were basically a Dana 30

[skidoo_j]

Currently my truck weighs 3,700 #s with me in it, a stock 2dr Rubicon JK weighs ~ 5,000 #s that's a pretty big difference!

Also wouldn't you have closer to an inch more ground clearance with d44s and 37" tires than with a d60 and 37"s?

 

 

Why go to the axles from a JK??? I thought TJ were direct bolt on? Is the TJ D44 weaker than the JK or are you wanting the extra width?

[Dirteatr717]

The TJ front just has a 44 housing the rest is a 30, I'd like the extra width for stability and with some extra work they can handle 37s just fine. Plus they're also lighter than one ton axles but not as strong, I don't need the strength even though it'd be nice to know I'll never break anything but I'd rather save some weight and money and plus it'd still all be "Jeep" parts 8) at the same time I'd like to be a little different :dunce:

Thanks again James for the pics and measurements! :thumbsup: :cheers:

[Dirteatr717]

I thought the jk front 44's were basically a Dana 30

They have larger axle tubes and if you sleeve them and add gussets they're pretty dang stout, so I've read. I'll also be able to put 5.13s in them and I think I've seen 35 spline rear axle shafts

[mvusse]

Maybe I beat on mine harder than some, but with a locked HP30 on 35s I go through quite a few unit bearings and u joints. The TJ Rubicon 44 uses the same u joints and unit bearings. Don't know about the JK ones, though.

[Dirteatr717]

I try not to beat on my truck, yeah for some obstacles you need a little skinny peddle but I try not to use it :D

I went on ruffstuff last night....

Coil buckets $40

Track Bar mount $30

Medium Truss $100

 

Synergy Ball joints $250 I'm sure Ill find something a little cheaper

Synergy Axle Sleeves $100

New perches $25

U-bolts $40

I plan on making my own gussets and shock tabs

So I'm at $585 excluding shipping charges just to bolt the axles in :typing:

and be able to drive my truck again Id need to find a set of 5x5.5 rims in the 15" flavor so I can switch my tires over to hold me over until I can afford 37s.... I know you need to grind down the calipers to fit 15" rims on JK axles but Ill have my grinder out anyway :yes: I need to find a set of axles for sale before I can even put a price on how much this is actually going to cost :help: I also plan on selling my rims and axles so thatll help with some of the costs, I'm also trying to sell my camaro WINK WINK

[Incommando]

Barnes is generally a little cheaper than RuffStuff and just as good IMHO. If you go to RuffStuff I *THINK* you can use the discount code PIRATE10 for a 10% discount.

 

JK's are hefty little piglets. The lesser weight of the MJ may help those axles survive.

 

I know the TJ front "44's" were hybrids but are the JK fronts pure 44 or a 30/44 hybrid like the TJ axle was?

 

Although the locker is not selectable, I have less about $1000 in my 4.56 D60 front with all new pads/rotors/bearings/hoses/wheel studs/ujoints & a Spartan locker. I have no worries about it holding up under the CJ with 38's. I have less then that in my shaved 14bolt rear with new locker and disc brakes. Just for a price comparison with the JK axles you have a line on.

 

[Dirteatr717]

I wish I could find a decent deal on a front 60 and rear anywhere by me they cost an arm and a leg, people think there gold all of a sudden :roll: I really don't want a boat anchor as a rear and with a little work JK axles will be fine for me :cheers:

The fronts have larger axle tubes and I'm pretty sure the Cs are different, Ill have to report back on that

[Incommando]

I would be curious about the axle stub shafts and unit bearing set-up. Although the D44 uses a larger ring/pinion, the TJ's versions at least were a low-pinion design that makes it closer in strength to a high-pinion D30 than many are willing to admit. I don't know about the JK but the way Chryco misled jeepers about the TJ front "dana 44" does not leave me hopeful. The fact that the JK D44 has serious bending issues and yet a true D44 was used under even heavier 3/4 ton trucks for decades without those issues makes me doubt the specs of the JK unit. If you have to sleeve and truss the axles, you can do the same to a HP D30. If your high pinion D30 has 297 u-joints, is trussed and sleeved, and maybe some super cheap C-gussets added, you are probably a lot closer to a TJ Rubi front at least with the same upgrades than folks think. I admit not knowing enough about the JK Rubi axles to make the comparison but, as listed above, I have my doubts.

 

For someone else reading this later and looking for better than factory axles for their MJ, you might consider finding a relatively cheap Dodge D60 pass drop front (mine was $300) then get a $75 adapter from 4wheelsupply on Pirate to mate a Dana 300 t-case ($200 or so) to your factory tranny and to match the axle drop and have not only a superior front axle but a cast-iron-cased gear-to-gear transfer case that is light years stronger than the aluminum-cased chain-driven 231. Add $100 for what a 14B goes for around here, $125 for the shaved cover, and if you are willing to keep the rear drum brakes you are golden with just adding your lockers. A shaved 14 bolt has +/- 2" more ground clearance than a factory one, is stupid strong, and butt cheap to buy. Unless you get a smoking deal that is far far cheaper than the average price of a set of JK Rubi axles (and then add the money you are going to upgrade its shortcomings & replace any worn parts) going to 1-ton axles is cheaper. Checking 10 for sale ads, the cheapest JK Rubi set was $2,300 and that was with no brake stuff at all on the rear and everything from the ball joints out gone on the front. The highest set was $5,500 with $3,500 being a common price. And remember this is a front axle that guys are ditching because of its issues. You can get a true D44 bolt-in aftermarket axle with an air locker for about $2,800 ( http://www.4wheelparts.com/Drivetrain-a ... _pl=101965 ) or about $2600 with an electric locker & even cheaper ( $2300+) with a mechanical locker or a LSD front. Add a cheap but stronger than a D44 Ford 8.8 rear axle with discs and you are done without any fab time, effort, or expense for the front and minimal for the rear. Add that you would not need sleeves, adapters, or new rims to the savings and... :D

 

On the front: Mine is 67 " WMS-WMS where a JK is 65" for WMS-WMS, so the width difference is not that great for anyone else considering that swap. A C&C 14 bolt is 63" so add some spacers to match up the track width front to rear ( or not..it isn't a huge deal) and call it a day. The brakes on my donor axles were perfectly servicable but I wanted to upgrade the rear and start fresh on the front. That is $650 of the roughly $1900 I have in my axle set with new lockers. The brake costs might be similar $$$ for the JK axle set if you wanted to start fresh with all new components.

 

$1900 for locked one-ton axles that are as close to unbreakable in this app as possible vs. $3,500 for a set of axles that still need to be heavily upgraded & even then are several factors weaker.... Your choice.

[Sir Sam]

The TJ Rubicon 44 uses the same u joints and unit bearings. Don't know about the JK ones, though.

 

The JK 44 stuff is stronger, bigger shafts, bigger ujoints.

 

comparison:

[Sir Sam]

I try not to beat on my truck, yeah for some obstacles you need a little skinny peddle but I try not to use it :D

I went on ruffstuff last night....

Coil buckets $40

Track Bar mount $30

Medium Truss $100

 

Synergy Ball joints $250 I'm sure Ill find something a little cheaper

Synergy Axle Sleeves $100

New perches $25

U-bolts $40

I plan on making my own gussets and shock tabs

So I'm at $585 excluding shipping charges just to bolt the axles in :typing:

and be able to drive my truck again Id need to find a set of 5x5.5 rims in the 15" flavor so I can switch my tires over to hold me over until I can afford 37s.... I know you need to grind down the calipers to fit 15" rims on JK axles but Ill have my grinder out anyway :yes: I need to find a set of axles for sale before I can even put a price on how much this is actually going to cost :help: I also plan on selling my rims and axles so thatll help with some of the costs, I'm also trying to sell my camaro WINK WINK

 

Hold the phone, if you take the buckets from a donor axle, or even your old axle, you don't have to buy any of that stuff.

 

You don't have to find 5x5" wheels, I'm going to get the hubs redrilled for 5x4.5" mostly because I already have wheels I want to run.

 

BUT, if you left the axles as 5x5" there are lots of JK moab wheels out there. You see sets of JK moabs for $200-$300 for a set, sure you would also need new 17" tires.....but you could recoup costs by selling your old stuff.

[Sir Sam]

I would be curious about the axle stub shafts and unit bearing set-up. Although the D44 uses a larger ring/pinion, the TJ's versions at least were a low-pinion design that makes it closer in strength to a high-pinion D30 than many are willing to admit.

 

This is very true, the TJ D44 is basically a glorified dana 30.

 

The JK D44 is very different, nothing is shared with the TJ D30 or D44. Bigger shafts, bigger u joints, Bigger Cs, bigger unit bearings....

 

The weak point seems to be the tube, for whatever reason some JK guys are having issues with it, I'm not sure how they are doing it, but the tubes seem to be flexing. This may not be an issue at all on out lighter MJs, but there are several methods to "gusset" the axle, one company makes an internal sleeve that essentially makes the tube thicker, plus there are gusset kits like prorock and so on.

 

I have no seen any issues with the Cs, just the tubes.

 

 

D30 knuckle on JK d44:

[Incommando]

Thanks for the info. I had not researched the JK 44 before and did not know the differences, which are obvious. I am pleasantly surprised because of the near-fraud Daimler pulled with the TJ's alleged D44 front.

 

Don't know why they are bending so often. I wonder if the suspension stresses are just right to make them susceptible to bending?

[Dirteatr717]

I don't know what people near you are smoking but 5,500 for a set of JK axles?! I've seen a JK30-JK44 set sell for $600 rotor to rotor! I actually can get coil buckets from a d30 for free and people are selling the JK takeoff rims with tires for 100-250 depending what tires are on them, they're not that sought after anymore here. I would stay with 15" rims anyway because tires are cheaper with smaller rim sizes and many people have 33s-35s and ive seen a few deals on 37s with 15" rims! Basically I would buy the axle sleeves, trackbar mount and perches or make UBEs. I probably wouldn't have to do ball joints until I put the 37s on anyway. If I can even find a set of axles for sale I really wouldn't have that much fab work or parts to buy. I have friends with D60s front and rear, 14b rears and I understand how strong they are but I don't NEED it. People are selling front HP44s around 5-800 bucks! :nuts: and I see D60 rears selling way above 400 whereas it seems they're around 200 every other part of the US :roll:

[Motion Offroad]

Just be careful buying a set of used JK axles; they may be cheap for a reason (already bent, cracked c's, etc). A lot of guys out there are selling their junk JK axles to cover the cost of replacements. You think your getting a deal but the axle's are junk.

[Dirteatr717]

Just be careful buying a set of used JK axles; they may be cheap for a reason (already bent, cracked c's, etc). A lot of guys out there are selling their junk JK axles to cover the cost of replacements. You think your getting a deal but the axle's are junk.

Very true! I found a JK30 and 44 rear for 1200 and I knew the guy who owned the JK an sold the axles for 600. Very wealthy man lol he bought a set of dynatrac 60s :drool: And sold the axles to a guy in my local club.