4x4 North

So, weighing some pros and cons here for my little diesel truck.

I need about a 63-65" width, WMS to WMS. I need a driver's drop front axle. I need it to be something that can actually be procured and has parts available.

If I make 250Ft-Lbs of torque and 180HP I'd be happy, currently the engine makes less than that. 2.72:1 tcase, no doubler. Probably going to put 33" tires on it. So it's not like anything too strong is required, but I want reliability. I also like disk brakes all around. Also I'll probably never really wheel this thing even, it's more just to drive and go places. Think overlanding that could be accomplished in a minivan.

Doing the math on the gear ratios, 4.10-4.56 should be fairly ideal.

Initially I was just going to grab a set of wrecker "regular" JK axles, the D30/D44 versions.
Pros:
-Right width at about 64"
-Should be strong enough, a few bucks on sleeves for the front axle would be cheap insurance
-Front is high pinion, which helps with the driveshaft longevity
-Mounts on the front axle can be adapted to what I'm doing
-I have wheels that fit, like lots of wheels, and it's easy to find more of them
-I have the conversion yoke to run a 1310 joint on the front, I'd have to find one for the rear but they're cheap
-Disk brakes, although the rears are pretty small and anyone who drives a JK will tell you they regularly wear them out
-Ground clearance is pretty decent with the D30, and certainly not bad with the D44
-All autoparts stores stock all the wear items

Cons:
-Boring
-Somewhat pricey
-Need a conversion yoke for the rear (they're cheap)
-Factory 4.10 gears can be had but not super common
-No selectable hubs (maybe that's a pro)
-Probably lots of other things I can't think of

Another idea was to spend more and get the JK Rubicon axles (HP D44/D44)
Pros:
-Width, strength, wheels, mounts, high pinion, brakes, etc are all the same
-4.10 gears are common
-Lockers that work fine as long as you change the oil
-More strength than needed, the as both as stronger than a normal D44 and JK guys seem to regularly run 37" tires on them with more power and weight than I have

Cons:
-Even more money
-Not sure if my front conversion yoke fits, still need one for the rear
-Not super easy to find a low mileage takeout set that's not mangled
-Still boring
-???

Then I thought about some older stuff... I know Snowracer has a F-150 D44 front and a set of 4.56 gears/install kit that he'd just love to sell
Pros:
-Width is reasonable at 65" I believe
-Gear ratio is right at 4.56
-Strong enough as far as balljoints, knuckles, gears and inner shafts go
-I have all the balljoints NIB to rebuild that part of it
-I have some flat top knuckles and Branik high steer arms, not that I think I can use them as is
-Selectable hubs... That stick out far so probably would have to buy Yukon hardcores

Cons:
-Cast in wedge axle, so you pretty much have to run a Ford radius arm style of suspension, and the actual strength of some fatigued out old cast wedges is maybe suspect?
-Outer axles suck. I have some abused Yukon Chromos that I could use if I had to
-Would have to confirm pumpkin position as it might have a date with my oil pan otherwise
-Any of the used parts will not be low mile or minty, expect to spend more than planned because that's what happens when you rebuild trash
-Swore I'd never build one again because they're poor value
-No clear choice for a matching rear end
-???




What else is there for some axles that fit my criteria?

I like the jk dana 30, it’s quite a strong unit aside from the biggest weak link in it is the housing, as c the rubicon 44 has the same issue. Even trussed they aren’t that strong so I’d skip the rubi front axle as all the jeeple thinks they are the swap answer and they are expensive and still have a junk housing. The jk d30 gears are something like 30-40% stronger than the xj hp 30 as well due a thicker gear set. On smaller/lighter tires and no 4:1 or doubler feeding it and modest power it would be a solid option. Parts are easily available. I paid $600 for my set front and rear and sold the rear for $500. Wreckers want a mint for jk diffs though.

Scoobienorth wrote: ↑Sat Mar 28, 2020 6:47 am I like the jk dana 30, it’s quite a strong unit aside from the biggest weak link in it is the housing, as c the rubicon 44 has the same issue. Even trussed they aren’t that strong so I’d skip the rubi front axle as all the jeeple thinks they are the swap answer and they are expensive and still have a junk housing. The jk d30 gears are something like 30-40% stronger than the xj hp 30 as well due a thicker gear set. On smaller/lighter tires and no 4:1 or doubler feeding it and modest power it would be a solid option. Parts are easily available. I paid $600 for my set front and rear and sold the rear for $500. Wreckers want a mint for jk diffs though.

The advantage of the Rubicon axle is it comes with a selectable locker for cheaper than I can buy and install one (that goes for the front or rear). The local wrecker wanted $4K for a set of low km takeouts that don't need "anything", which may sound steep, but once you price out two ARBs or Zip lockers, install kits, a compressor that doesn't suck, and upgrading the air lines to something that won't fall apart, you're at the same price. I'm not really wanting to run auto lockers with this as the street driving versus actually wheeling ratio is going to be way too high, but not having lockers at all is terrible. The only compromise I could see there long term would be to run a selectable in the rear and a Truetrac or other helical gear LSD in the front, although I may have not totally thought that out.

I can't really see wrecking the front Rubicon housing unless I really F up. With the sleeves and gussets you're probably as strong as most of the early D44s, excluding the F-250 ones with the big/thick tubes. I can't fit a truss though, or I don't think I can.

I can't see breaking the D30 either. JK guys will run them with 35s and have them hold up sorta okay with sleeves and gussets. The average JK trail weight is probably 5200lbs, and they're pushing a lot more power than I ever will right out of the box.

I’ve talked to Enrico when I bought my jk diffs quite a bit as my original plan for my wj was to use the rear as it’s got my tone rings to keep my speedo and trans happy and get a hp44 front. I was asking about the ability to hold 37’s and if the ring and pinion would hold up at 5.13 in the d30. He said quite openly there housing will fail first and will fail even trussed and beefed up. I believe a lot of the internal failures of the jk axles come from what he was saying and related to flex. The rubicon not needing gears and internals definitely adds value and time savings if you leave it as is. I feel quite comfortable saying if I had decent suspension at all with jk diffs where I could get any sitter at all it wouldn’t take me long to kill the housing or C’s. Stock axles and ring gears would be fine, I don’t think I’d break very many aside from spider gears.

99-04 superduty diffs even cheaper if you buy the dana50 front diff and stiff marginally stronger then a gayk 44 whick should be perfect for a jeep buid

pointsnorth wrote: ↑Sat Mar 28, 2020 9:12 am 99-04 superduty diffs even cheaper if you buy the dana50 front diff and stiff marginally stronger then a gayk 44 whick should be perfect for a jeep buid

I actually haven't seen a D50 for sale any time recently. It's a tossup on the strength between the D50 and the JK D44 in some ways, the advantage of the D50 would be the housing/tubes/knuckles and you could run bigger ujoints. The JK D44 ring gear is probably almost as strong given the change in gear cut and the bigger bearings.

Main issues with them is they're heavy. I don't have any numbers for the JK D44, but the 99-04 Stuperduty D60 is about 540lbs and there is no way the JK D44 is even close to that. It's also a little too wide at 69" WMS. I could hack 4" off of it and build some total bastard axle, which would be amusing, but the pumpkin might be too big and too centered to clear the oil pan then (assuming I shorten the long side). Shortening the short side leaves you with not much (or any) tube. I'd definitely have to take some measurements to see if that would even be feasible either way.

And a D60 front with 33" tires sounds pretty 'tarded. Shaving 2" off is doable, not sure how much more you could go.

unless the price was super cheap, can't think of any reason to run JK D44 instead of D30/44 combo or an older 44/whatever rear that matches combo

lighter weight is going to be well worth it compared to strength. for something like that, running spacers would, honestly, be just as reasonable to get the width you want rather than retubing and custom shafts and shit. small tire, small power, not slamming off boulders all add up to easy enough stuff that a nissan titan could survive

I think options are pretty limited with most vehicles ifs these days, jk axles will be the norm for light axle swaps. The older stuff is narrow and only getting harder to come by.

Provience wrote: ↑Sat Mar 28, 2020 9:37 am unless the price was super cheap, can't think of any reason to run JK D44 instead of D30/44 combo or an older 44/whatever rear that matches combo

lighter weight is going to be well worth it compared to strength. for something like that, running spacers would, honestly, be just as reasonable to get the width you want rather than retubing and custom shafts and shit. small tire, small power, not slamming off boulders all add up to easy enough stuff that a nissan titan could survive

This build is to address what I felt I didn't do right in the last Comanche build, and not repeat those mistakes. In so doing I will make new and different mistakes, and probably have to address those in the next build.

I have spacers/adapters on the last one, and I honestly hate them. Even the smallest amount of maintenance turns into removing them and reinstalling them, which means annoying torque checks and always wondering about them. I spent some time playing with my last JK in this regard too, since I put spacers on it when I went to 33" tires, and found that adding the spacers made the most negative impact on the highway driveability due to the scrub radius change, it wandered like a reserve dog with the spacers and tracked fine without them. Adding massive amounts of caster might have bandaided that, but that turns into hacking the Cs off anyways. So basically I don't want to run spacers, I want to hit the width correctly the first time and have the scrub happy, and then leave it alone. I'm aware I could solve half the issues of the spacers by going to different wheels, but it won't change the fact it will drive poorly in comparison to having the scrub correct.

There isn't really a lot of axles in the 64" width range. 69" yes, 60" yes, in between not really.

Axle availability is also an issue. Lots of stuff doesn't seem to exist anymore. 15 years ago I f'd around with a lot of 70's front D44s, and they were easy to find. Now not so much.

Scoobienorth wrote: ↑Sat Mar 28, 2020 9:58 am I think options are pretty limited with most vehicles ifs these days, jk axles will be the norm for light axle swaps. The older stuff is narrow and only getting harder to come by.

Yeah, it's hard to find stuff.

I have a Wagoneer LP D44 front here, well a few of them that would add up to a whole one. But they just suck being low pinion and 60" wide.

Scott Cee AKA 2drx4 wrote: ↑Sat Mar 28, 2020 10:01 am

Axle availability is also an issue. Lots of stuff doesn't seem to exist anymore. 15 years ago I f'd around with a lot of 70's front D44s, and they were easy to find. Now not so much.

that's no shit :( for how often as those things used to be free or scrap.


FJ80's are ~63" wide or so

i feel ya on the spacers, but didn't see it mentioned so figured i'd toss it out there. it's certainly the 'easy' button. despite being a pain in the ass, are you open to the idea of doing a hybrid 60? run an 8.8 or 44 or whatever smaller center chunk you can get handy and use the dana C's? custom shafts aren't that expensive and even being necked down wouldn't be too big of a deal.

you'd be able to save a great many metric measures of weight by using the lighter diff housing and smaller/lighter tubes, have the width and drop that you want, and have good steering.

blown up D60 should be reasonably cheap enough

tacoma drop trail mart housing set for fj60 axle shafts gets you too 58 then swap ifs hubs and a tacoma brake swap will get you too 62. toyota parts are still plentiful in junk yards and trailmart in van can over night most things

and if you want to scrounge up parts rather then buy them youll need a short side shaft from a fj40
and longside from a minitruck diff
hubs are 86 and up truck or 4runner turned down 5/8 to fit slip over tacoma rotors

Provience wrote: ↑Sat Mar 28, 2020 12:01 pm

Scott Cee AKA 2drx4 wrote: ↑Sat Mar 28, 2020 10:01 am

Axle availability is also an issue. Lots of stuff doesn't seem to exist anymore. 15 years ago I f'd around with a lot of 70's front D44s, and they were easy to find. Now not so much.

that's no shit :( for how often as those things used to be free or scrap.


FJ80's are ~63" wide or so

i feel ya on the spacers, but didn't see it mentioned so figured i'd toss it out there. it's certainly the 'easy' button. despite being a pain in the ass, are you open to the idea of doing a hybrid 60? run an 8.8 or 44 or whatever smaller center chunk you can get handy and use the dana C's? custom shafts aren't that expensive and even being necked down wouldn't be too big of a deal.

you'd be able to save a great many metric measures of weight by using the lighter diff housing and smaller/lighter tubes, have the width and drop that you want, and have good steering.

blown up D60 should be reasonably cheap enough

The FJ axles are the wrong drop. I guess you can do some retarded things like flipping the housing to fix that, but I don't have much experience with them. They're all lowpinion too, or so I believe, so a bit of a strike against them.

I've got a spare 90-something (I think a 96?) HP D60 and a 2004 not-so-Superduty one. I'd have no hard feeling about cannibalizing either of them. I think I've actually got a set of cut off BJ Cs too, so that's another option. Finding a decent HP D44 for a donor might be a slight issue, the cast wedge one doesn't have enough tube to do much with, and DOM that large costs me a metric fuckton because the only place in town that deals with it enjoys robbing cash customers. That said I can get tube elsewhere if it isn't workable.

The 04 outers would probably be better as the hub is a lot more low profile, IIRC. Still not as good as an 05+ though.

pointsnorth wrote: ↑Sat Mar 28, 2020 12:57 pm tacoma drop trail mart housing set for fj60 axle shafts gets you too 58 then swap ifs hubs and a tacoma brake swap will get you too 62. toyota parts are still plentiful in junk yards and trailmart in van can over night most things

and if you want to scrounge up parts rather then buy them youll need a short side shaft from a fj40
and longside from a minitruck diff
hubs are 86 and up truck or 4runner turned down 5/8 to fit slip over tacoma rotors

Interesting. But what's scrub radius like if you do that? It sounds like it basically just keeps adding stuff outside of the kingpin center until things fit. I think most Toyota owners have never driven anything with the scrub radius even moderately correct...

I also have zero Toyota parts in my possession, so there's a uphill battle to using them.

Here's another question, how much weight does a hybrid 44/60 actually save versus a regular 60? How much more is it than a D44?

I guess I could go weigh some parts...

FJ80 is high pinion, flipping the axle to drivers drop would probably be the easiest thing.

most people shy away from the 80 axles because they use an 8" ring instead of the 9.5" used on the 60/40 stuff. but a stock 80 has the width, is high pinion and would meet the things you need to do and be the correct width. pinion drive flange makes it super easy to adapt drivelines and factory elocker is an option

my fj60 axle with minitruck ifs hubs is like a 3 or 4" from centerline with a 37" tire with a neutral/centered wheel. not something i'd recommend for a 31" tire unless you want to run a deep dish factory style wheel. b

here is a rather shitty picture, the IFS hubs add ~1-1/2" compared to the stock hubs


edit: the worst/most expensive part about the fj80 is the price of the high steer arms, you shouldn't need those even if you do different steering and just add to/modify the stock arms