I've been mulling options for axles because Ford's TTB front suspension design is the engineering equivalent of Chernobyl. I have a 1985 F350 4X4 that I bought a little over four years ago. It had a blown 460, so I picked up a first-gen Cummins with the intent of swapping it in. Then, after it had sat for about three years, I got the idea to swap in an International DT360. Now, I realize it would be a better option for my long-term plans to buy an early Super Duty F550 chassis to swap the DT360 in to. Props to SuperHatch on PSN, I'm essentially copying his idea.
Because of this shift in priorities, I have a perfectly usable dually F350 4X4 crew cab that I can snag whatever I want from. And the first thing is axles.
One of the changes that is needed is gearing. The F350 axles are 4.10 and the Bronco axles are 3.55. I really liked how the Bronco behaved on the freeway with the higher gearing, so I will change the Sterling and Dana 60 gears to 3.55s. Since the axles will be out from under the frame, I'll give them a thorough going-through as well.
I went out to the garage this morning to take some measurements to see how close the front and rear axles are in width between the Bronco and the F350. I also measured the M5OD length to compare it to the E4OD I just picked up this past weekend.
Here's what I came up with (these measurements are all fairly close but not exact):
1. The M5OD is 29 1/2" long, while the E4OD is 31 3/4". I think this will work out in my favor, because of the now-needed change in front axle clearances. I will cut the front crossmember off (that the nightmare of a front axle currently pivots from) and fab up a DOM crossmember in its place further forward to carry the weight of the 4BT. My idea is to shift the 4BT forward the 2 1/4" difference. (Truthfully, I think the only thing that will be an issue with where my engine eventually ends up is the oil pan to D60 pumpkin clearance.)
2. The D44 TTB is 58 1/4" wide and the D60 is 60 3/4" wide. I measured from the inside of the dust shield to the inside of the dust shield, but I think it's a close enough measurement for my purposes. The F350 is a dually, so I will need to change out the hubs and spindles. I figure I can find these easily enough on any '80s or '90s F250 4X4 in the junkyard. I'm also going to keep my coil sprung front suspension, so I have some reading, thinking and fabrication work to do on the Dana 60.
3. The 8.8 rear in the Bronco is 60 1/8" wide and the Sterling 10.25 is 62 1/2" wide. This surprised me, because I read that the dually Sterling rears are four inches wider than the non-dually Sterlings. I had assumed that the 8.8 in the Bronco was going to be the same width as the non-dually Sterlings, but I guess not. This measurement was taken from the inside of the drum brake flange welded on the end of the axle tube to it's counterpart on the other side.
Really, it just boils down to choice. Would you rather have this:
You must be registered for see images attach
or this?
You must be registered for see images attach
Pretty much a no-brainer, IMO.
EDIT: This Bronco has an 8.8 rear axle.