Thanks for the input. I really enjoy the discussion..............
In my limited experience, I’d rather run a built 9 inch, front or rear, than a built Dana 60 (though I’d rather pay for a built Dana 60), but I think you’ll get people who fall on both sides of that discussion. Again, I’m just referring to the center section. The Dana 60 is much better when you get to the ends of the axle.
Thank you, I do too, and if sharing it helps someone make a decision of one part over another they can make it open minded and know what the potential pitfalls or successes are.
I'm with you on the building part, I would build 9" stuff all day long, rarely do I build Dana's, I hire someone for that, its just a whipping as far as I'm concerned. There is a reason we use 60 or even better 70 front parts for steering. Dana 70 is what Reid king pin parts are based off of, happen to know where their original design samples came from...... Dang I'm showing my age LOL. As for rears the Full Float parts are the way to go for sure whether they come from a D60, D70, D80, Sterling, 14 bolt or AAM. The advantage to using 14 bolt over the others is you can use a D60/70 front hub to get any wheel bolt pattern you want and double spline axles, which in theory are stronger than a flanged axle, Although I've never broken a full float flanged axle at the flange, I've sheared the bolts off due to a builder not using appropriate hardware but never the flange. I have broken the flange off of a semi float axle, it does happen, I know of 2 bronco's that have done this on the street, scary. I've also seen 1/2" wheel studs shear on 5x5.5 bolt pattern, scary being chased down by a 40" tire 1/2 full of water thundering its way down a mountain with no vehicle attached to it.
A bit of an undiscussed trivia. In hard core rock crawling its common to see front tires 1/2-3/4's of the way full of water, the added weight in the tire increases its traction considerably. Also adds slow speed stability. Think about how hard it is to roll an axle over with tires on it sideways, now make it 500# heavier with the weight focused on the bottom of the tire, it will be even harder. Its guys doing that stuff that have driven the development of the parts and technology we have today that make our rigs as strong and well performing as they are.
I recently built a semi float 60 for myself and really struggled with the "has to be full float", ultimately I caved and did semi float with SET 20 bearings, and 11" Ford drum brakes. I really wanted to do SET 80 bearings but they are expensive, uncommon and I had to machine my own ends. I was also going to have to do my own brakes to do FF and again, expensive and time consuming with custom parts. The axle I wound up with has off the shelf available virtually anywhere at a reasonable price parts. The only custom part is the axle shafts because it truly is a custom built axle to fit the application and there were no common shafts that would work. It really came down to brakes being the ultimate deciding factor, in this application an 11" drum is all that there was really room for without changing other design factors that I didn't want to change.
