Today I put the tires on my front and back axles (the middle one will be a while getting back to me).
I actually *started* to put the tires on the front axle yesterday, but I didn’t reckon with the floppiness of the two ends with no tie rod to hold them together:
So they sat this way overnight while I tried to figure out a way to get everything to cooperate with me. My first thought was to level it out so the pinion was pointed in the right direction (toward the back of the Jeep instead of at the floor). However, when I tried that, everything just flopped the other way and the pinion ended up pointing at the ceiling. So I had to think of a Plan B. I finally came up with a “temporary tie rod” (actually a broomstick and some lightweight rope) to keep the tires in one position relative to each other, and then I used the rest of the rope to lasso the pinion and keep it from rotating back toward the floor:
Then I tackled the back axle. By comparison, this was a piece of cake. Since the ends are fixed, I simply jacked up one end and put the tire on, repeated with the other end, and voila!
I guess this is as good a place as any to give you the specs, so here goes.
The three axles are all 60 inches wide, from wheel mounting surface to wheel mounting surface. I measured the back axle’s overall width this afternoon with the tires on; it measures 74 inches. Since the Jeep’s body is only 60 inches wide, the tires will extend past the tub about 7 inches on each side. [This detail will become relevant eventually, when I start work on the body.] The axles all have the same gear ratio of 4.57:1. This is especially important for the back two axles, of course, since they’re always going to be connected and both will always be powered. If they didn’t have exactly the same gear ratio, this setup wouldn’t work. Having the front axle match the gear ratio also makes life simpler when I’m in 6wd. It’s not *as* important for the front-axle ratio to exactly match the back axle(s), because when your front axle is also driving, you’re typically on soft surfaces (dirt, mud, snow, air) that allow wheel slip, but if they are the same, then slip is minimized.
All three axle housings were built by Currie Enterprises, based on a Ford 9-inch axle design. The center sections for the front and middle axles were also built by Currie and include ARB Air Lockers. Both are a low-pinion style of center section. The center section for the back axle is a high-pinion style, was built by TrueHi9, and also includes an ARB Air Locker. All three axles have disc brakes; the back two axles also have small drum brakes for the parking-brake system. I plan to use these parking brakes in pairs, with the driver-side brakes connected to one brake lever and the passenger-side brakes connected to a second lever. This will allow me to manually brake one side or the other of the back two axles, helping reduce the Jeep’s turn radius.
I’ll be running 35-inch-diameter tires on the Jeep. While they’re not super-huge – at least, not in today’s world of 40-inch and larger tires on Jeeps – they’re plenty big for my purposes. They also satisfy one criterion for an expedition I hope to be invited on someday: the Ultimate Adventure that’s put on every year by Petersen’s 4Wheel and Off-Road magazine. Among other things, every vehicle on this adventure must be on tires at least 35 inches in diameter. I don’t know yet what brand I’ll be using, or even what tread style (all-terrain or mud-terrain). The wheels are 15×8 chrome-plated steel. I chose them because they get the job done and they’re reasonably priced.