Axle swap in a 78cj5

78CJ5

New member
Hey guys!

I have a 78 cj5, l6, t18 transmission (t18-1b is the stamp). I haven't confirmed the transfer case. AMC 20 rear, dana 30 front.

Backstory

I live in the flat lands of South Dakota, so my main and practically only wheeling is mud and dirt hills, although rocks do tend to stick up in pastures. 90%+ of my rigs time is daily driving. I run 33" tires but 35s or 37s may be in my future depending on how this goes.

I rebuilt my AMC 20 at 16, and well... didn't know enough. It works nicely but because the lash wasn't set correctly my pinion seal leaks. It has solid 1 piece axles (if I remember right I used alloy usa). I also might have a plan for this axle in something else.
The dana 30 front is more or less shelled from when I limped around in 4x4 when the rear had 2 piece axles that failed. At least it will need a new ring/pinion/rebuild kit.

The leaf springs also go under the axles, and the PO used a rancho add a leaf and added...many... leafs. My suspension is practically solid, and to add to that the bottom leaf sticks straight out and they love to carry weeds/bash into rocks.

I'm looking into full length axles. I want this because following another vehicle is pretty hard with the shorter axles as I'm bouncing from wheel trail to wheel trail. This is mostly an issue when going through snow. I also would like to go wider to give me a more stable stance. I currently have 6" fender flairs and I'd like to tuck the wheels between them (73" edge to edge...this would include wheels/tires installed).

My current springs that sit on top of the added leafs are in bad shape (bent, cracked, broken, military wraps coming undone). I don't want to sit up higher than needed to fit the 33/35 inch tires, I also want to go SOA. I'm assuming just about any spring is going to be more comfortable than my current set-up but it would be ideal to get the best ride quality springs.

Getting to it now,

What I want (order of importance):

A more comfortable ride.

SOA and high steer. See "rocks sticking up out of pasture"

Wider axles that when wheels/tires are mounted, measure 73" from the outside of one tire to the outside of the other. I'm sure rim backspacing gives us a little play here. 12.5 or 13.5" wide tires are the most I run.

Stronger axles. I plan on getting lockers front/rear at some point, and the most power I'd give them is a mild 350...but keeping the i6 for now.

What I've researched:
Waggy springs/axles or dana 60s from a rare gem of a ford.

I was pretty set on the dana 60 option but am now leaning towards dana 44s as I don't really beat my axles up rock climbing, and the i6 isn't dumping loads of power. I also read the dana 60s weigh a ton, and the 44s have more ground clearance?

I went to school for mechanical engineering and was a welder for a couple years, as well as hobby welding for most of my life, so I'm not too bad off here. There are loads of junkyards/salvage yards in the area and axles probably won't cost me much due to a low demand.
What's my best option here? Buy a ?year waggy and rob parts?

I appreciate your response!
 

A good combo that I run is a Waggy d44 front and a rear d44 from an Isuzu Rodeo. The 'Zu axle has disc brakes and 6-lugs to match the front axle. No matter what you do you'll likely need to outboard your front spring hangers.

A better axle than the Waggy d44 front is a Ford HP d44 from a '78 or '79 F250. It has thicker axletubes and a high pinion for better clearance. It's full-width, my plan is narrowing the two I have to run Waggy axleshafts.
 
If I remember correctly the waggy axles should be around 60" wheel mounting surface to mounting surface. Add your tires and you should be close to your 73" goal. Bounty, just curious, but why did you choose the rodeo 44 over the waggy 44? was it just for the disks? How are the ring and pinion compatibilities with waggy ring and pinions, Do you need pinion yoke changes for diff driveshaft ujoint sizes for a jeep? brake proportioning valves?. Im asking because Im getting ready to save up for 44,s and disk would def be better than drums, but the budget will dictate. OP I didn't mean to hi-jack your thread, but since it pertained to 44,s I thought it would be appropriate.
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OP I didn't mean to hi-jack your thread, but since it pertained to 44,s I thought it would be appropriate.
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That's perfectly fine I plan on getting disc for the rear in some way or another.

I really don't want to chop the axles I choose. I'm also ok with getting new rims as my tires need replaced anyways.
 
Eric M, good catch. He'd need an early Waggoner front axle with pass side drop.

As for the Rodeo rear d44, it comes with either 4.10 or 4.30 gears, has a tall ratio carrier with a thick gearset so if regearing you'll need thick gears or a low ratio carrier. It also has one pinion bearing different than most d44's but still commonly available. Comes with a pinion flange that is easily swapped for a yoke. Having rear disc's factory is a nice option
 

Honestly, the posibilies are endless.
If I were you, I would search for a chevy D60, Dime a dozen and can be bought a lot cheaper than the ford counter part (in my area) and are arguably stronger. For what you will pay for a early FSJ D44, might as well buy a D60. For the rear, since ground clearence is a concern, search for a full wideth 9" or a D60 from an early 2wd chevy truck or late 70's ford truck.

Nothing wrong with D44 axles, they do have limitations and you need to consider exactly what you are doing with the truck and your needs.
 
Honestly, the posibilies are endless.
If I were you, I would search for a chevy D60, Dime a dozen and can be bought a lot cheaper than the ford counter part (in my area) and are arguably stronger. For what you will pay for a early FSJ D44, might as well buy a D60. For the rear, since ground clearence is a concern, search for a full wideth 9" or a D60 from an early 2wd chevy truck or late 70's ford truck.

Nothing wrong with D44 axles, they do have limitations and you need to consider exactly what you are doing with the truck and your needs.

Driving it around is mostly what I'm doing and I hate stuff catching on rocks sticking out of the ground I should be able to clear if it wasn't for a 5" pack of springs under my axles. Not many people wheel around here because of the lack of places to go so I'm sure there's tons of D60s at the yard. What it's gonna end up being I think is I'm gonna go out, measure around and just pick something. Obviously I'll try to find the best option, hence me asking on 7 different forums lol.
 

If you not going to wheel, just SOA with your stock axles or find some wide track CJ axles. I see no need for you to go any beefier if you do not intend to wheel it. If you are hell bent on having wide axles, find a 80's k20 and snatch up the 10 bolt front and 14 bolt rear. if it has external hubs it is a 10.5 ring gear if it is semi float, 9.5 ring gear. Both are more than capabile of driving around duties.
 
I've made up my mind for now to go with the rock equipment granite kit from ok4wd. Rock Equipment Granite Kit | OK4WD

I'm going with the ARB Suspension (OME) springs which give me around 2-1/2" lift. I also plan on flipping my tie rods to get that clearance I want. From the pictures I've seen it looks like the springs aren't gonna be too bad being under the axle.

This will allow me to get a set of dana 60s and build them up, as well as give me time to plan out my coilover suspension.

Thanks for the input guys! I'll be sure to start my own build thread once I get rolling on this.
 
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