Before Custom Axles, There Were Garages And Grinders
In some ways, Jeep overbuilt their axles in the early years. Yes, there were some weak links here and there in the MBs, but the front- and rear-model 23 axles were over-engineered considering the 60hp engine used then. Improvements with the first civilian Jeep in '46 included a stronger Dana 25 up front and the short-used Dana 41 in the rear. With 1949 came the ubiquitous Dana 44, and things stayed that way until 1975 when there was a switch to the AMC axle and then back to Dana around 1987.
There was a big and much-needed change in the 44 used by Jeep in 1970. This was the introduction of the flanged one-piece axle that replaced the tapered-shaft and keyway two-piece axle/hub design of the Model A Ford era. Actually, this early design worked just fine (with the tires and wheels of that time period, that is). But with the advent of wider tires and wheels, the load increase caused tapers to loosen up and keyways to crack. Once this happened, the hub would just spin on the shaft and sometimes even the axle would break just at the end of the taper. Say goodbye to the hub, wheel, and brakes.
However, a lot of people, including myself, used these axles hard and with some fairly large tires for the time period. In fact, I used them on my first true race vehicle with some 34-inch tall tires. The big secret, as I remember it, was to make sure the nut was always kept tight at the recommended 175 lb-ft of torque. OK, I never owned a torque wrench with that kind of capability, so that resulted in putting my weight on a 1 1/2-foot breaker bar with a pipe on the end of the handle. I broke a few breaker bars this way, as well as earning a few skinned knees.
Ford pickups and some Mercury cars in the '50s used a flanged axle version of the Dana 44, but, naturally, it was wider. The wide-track thing wasn't as popular then as it is now, so in order to use them, narrowing was necessary. It was hard to find a shop that could re-spline an axle in the '60s. So, believe it or not, we would actually cut the shaft, take a piece out to get the desired length and weld the splined end back on! It was a real sophisticated process we used. A section of axleshaft would get cut out on a band saw, then we would chuck the axle ends up in a lathe and bore a 1/4-inch hole about 1 inch or so in the ends. A round piece of rod inserted in the holes brought the ends together more or less centered, and we would then weld the two shaft pieces together. By all means, they should not have held and some didn't.
We would then cut the axletubes down to the proper width using the axleshaft as an aligning bar when the tubes were re-welded. Most of the time, the tubes just got butt-welded together--sometimes a sleeve was used. Crude, but it seemed to work. But remember, we weren't working with 36-inch tall tires back then. THE DANA 60sIn the '70s I came across a Ford heavy-duty 1/2-ton rearend that was actually a Dana 60 with a 5-on-5.5 bolt pattern. These axles had the good Spicer Power Locks in them. OK, it didn't have the high-pinion that present-day long-travel suspension requires, but the larger ring-and-pinion was a great asset. By now I had found a machine shop with the capability of cutting axle splines. No more welded axleshafts for me. But again, I used the axleshaft as an alignment bar. It just so happens that most of the early Dana 60 full-floating rearends also use the same spline count and diameter shafts as the Jeeps and Scouts. Many years later, I built several Dana 60 rearends using Jeep or Scout flanged axleshafts and housing ends. By then I had a full-length, 1-inch-diameter alignment bar with corresponding end blocks to hold things more or less straight before welding the housings together. The early '70s saw a few other heavy-duty 1/2-tons, such as the one from International Harvester with the same rearends. Some Dodge performance vehicles and 440-powered Ram Chargers also used this rearend. Cutting one side down and having the axle re-splined gave you a pretty decent rearend.