Gearbox Assembly

Removed front of the snowblower, unbolted the augers, drive sheave and unpinned the secondary thrower. Pushed the assembly out of the bearing, and removed the shear pins on the augers to get them off the cross shaft. Reversed the order, on the new gearbox, and used a bit of Loctite 271 on the threaded sheave to shaft connection (now I know why the sheave came with it, the original was keyed to the shaft, with a center bolt to hold it on).
Tightened up the bolts, checked for the correct orientation of the augers, bolted the front back on the blower, put on the drive belt, chute and belt guard.
Tested, and it's blowing snow like it should. No special tools, and it's a pretty straightforward, once the front is removed from the engine section. Blocking that engine section up, so it doesn't fall backward when the front is removed, is the way to go.