7 Seater, Rock Crawler, Street Legal on a Budget?

[Death Wobble]

When that 10" subwoofer is cranked up, it'll feel like you're sitting on massage chairs!

[Mike DeChristopher]

One gallon of herculiner, lots of rustoleum and undercoating, all new fluids, an assortment of seals and gaskets, new 2.5" stainless custom welded exhaust from Red Run and that about wraps it up. I've put about 300 miles on it to date and made a trip to aoaa and RC with the club last month with no issues and tons of fun.

https://goo.gl/photos/sUqwLageWuxeah3n7

[Mike DeChristopher]

So after wheeling my rig quite a bit I decided it was time for an axle upgrade. Early on I had decided not to mess with the axles right away due to the time and cost. I feel like I did pretty well with the Dana 30 and 35 since I only broke 2 front U-joints over the past ~1.5 years with 36" swampers.

My goal in the swap was to be able to jump to 38" swampers, keep 4.56 gear ratio, maintain my existing ground clearance & track width, and minimize cost.

Thankfully there's a bounty of info on the web for 1 ton axle swaps.

For my swap, I chose an '88 Ford F350 front axle and a mid-80's cab and chassis 14 bolt.

The 14 bolt comes in 2 widths: 63" and 67". I found a 63" rear with 4:56 gears on CL for around $100. It had huge drum brakes and was an oily rusty mess.

The Dana 60 is much wider at 69.25". The 85-91.5 axle uses kingpins (desirable) and the spring pads are located 3.5" offset compared to the sought after 78-79 version. In a strange coincidence, the location of the driver's side spring perch on the '88 Dana 60 was an exact match to enable a ~63" track width on a YJ! This means that I would only need to shorten the passenger side.

I found a Dana 60 on CL with 4:56 gears for under $1000.

[Mike DeChristopher]

The 14 bolt is very robust. It boasts a 10.5" ring rear. Unfortunately the result is a housing that hangs very low. I elected to reduce the diameter of the ring gear and shave the bottom of the housing. I completely disassembled the rear and took the housing and ring gear to work.

I used a conventional lathe and carbide inserts to reduce the diameter of the ring gear from 10.5" to 10.0". I took my time and the result was awesome. There are those who say the gear is too hard to be cut with carbide but that's not true. I did need to sharpen the carbide frequently. The intermittent cut across the teeth does cause the carbide to chip once in a while.

I made a fixture to hold the housing on the bed mill. It supported the axle at the tubes so I could rotate the housing to the desired angle. I milled 1.5 inches off the bottom of the housing. I chose to mill parallel to the ground (I already knew my pinion angle). Others chose to mill parallel to the pinion but this results in more housing material removed without any increased ground clearance IMO.

After I shaved the housing, I machined a pocket into the base to receive a 1/2" thick flat steel plate. I then machined the plate to fit the pocket added a groove in the center to clear the gear. There's about 0.125" clearance between the plate and the gear.

I took everything home and welded the plate. Prior to welding I used a grinder and added a healthy bevel to the weld joint. There's a lot of differing opinions on how to weld the plate. I chose to preheat the housing and use nickel rod in my stick welder. I used a Mr. Heater on a 20# tank and some aluminum foil to heat the housing. It worked really well (and fast) and I was able to hold the housing at 400F with good consistency.  I made multiple passes on the outside as well as the inside. It welded like butter. I recommend the nickel rods. They're expensive but it made the job seem easy.

After the plate was welded I allowed the housing to cool very slowly. I turned the heater down over the course of a couple hours and eventually turned it off. I ground the weld flat and took the housing back to the machine shop to face off the plate flush with the differential cover mounting surface.

https://drive.google.com/open?id=0B5rIHifrzBStZFJ0Z3Y0SjdUN1U