I took a few pics of disassembly to help anybody that wants to know what the inside of the spindle looks like and what you're getting into if you want to rebuild it.
To loosen the pulley nut, I wrapped a rope around the pulley and fed it through some holes in my work bench. With the rope tightened underneath, it holds the pulley very well without any danger in breaking the cast pulley. With a few swift hits to a big crescent wrench with a BFH, it came off pretty easy.
I knew from manual that the pulley sat on a tapered part of the shaft so it should just slide off with a little coaxing. I used an assortment of screwdrivers to find the right thickness that would allow me to apply pressure between the bottom of the pulley and the to top of the spindle housing. After letting some penetrating oil do its thing for awhile and driving the screwdriver through all three openings (repeatedly for about 30 mins), the pulley eventually let go of the shaft.
When you take off the pulley, you're faced with this seal. This seal was the hardest part to deal with. There's no way to remove it without tearing it out. After staring at it for a few beers and trying to figure out how to do this, I resorted to jamming a big punch (with a sharp end) into any crevice available until it started to buckle. The photo shows the top part of the seal only. Underneath this is the rubber part that is as wide as the housing and underneath that is the other side of the seal, which is metal. The part number printed on the seal is National 43493XA1 but in the dealership catalog, the part number was 117275C1 and they cost $15.50 each.
With the seal removed, you can see that a large snap ring holds the top bearing in. I have regular automotive snap ring pliers and they were almost no match for this thing. It was much stronger than a regular snap ring like what you'd see on a typical u-joint on a car. Using my pliers, I was only able to lift the ring out of it's channel just slightly so a small screwdriver could be placed to keep it from going back in. Using another screwdriver, I had to work the ring around, easing it out of the channel as I went. In case you're thinking needle-nose pliers might work against this - think again. The ring was too strong for that.
With the ring out of the way, the entire shaft assembly came out easily by tapping on the shaft from the bottom. I had to use a socket extension to help hammer it through when the shaft receded too far into the housing. The top bearing is able to come out like this without sliding down the shaft because there's another snap ring on the other side (the bottom side).
Here's the old shaft next to the new one I bought. The shaft part number is 73968C2 and it cost me $134 at the Case/IH dealer. From top to bottom of the shaft, the order of parts are: large spindle nut, top seal, snap ring that fits into groove in housing, bearing, snap ring that fits into groove in shaft, slinger (cone looking thing), another snap ring that fits into groove into shaft, bearing, snap ring that fits into groove in housing, bottom seal, (washers, blade, and jam nut not pictured).
The bearings cost about $35 each and mine were fine so I decided to reuse them. I normally wouldn't reuse bearings like this but it's a mower, not a wheel bearing. A puller and some coaxing with a brass punch from the other side were able to remove the bearings fairly easy.
I used my vise to help me put the snap rings back on the shaft.
The bearings were repacked and all parts were put back on in the order they were removed. The bearings were installed using a brass punch and working around the bearing a little at a time. If you've installed new races into a wheel rotor, it was similar and about the same tightness.
Overall, this was a pain in the ___ but the mower was fixed for about $165 and a six pack. I've mowed the yard twice since the repair and it mows like a champ.
