I have a 915 that siezed the bearing in the 5th gear on the pinion shaft. Do I split the gear or is there some other technique to pull the gear off the pinion shaft? Can't fit a puller under the gear.

Unless it got REALLY hot, the inner race should nearly fall off the pinion shaft. Support the gear and knock on the end of the shaft with a hardwood dowel and a hammer. Often, you can invert the shaft, and slam it down on a piece of sturdy wood on the bench top or floor. The Cap'n

It seized hard enough to shear three teeth of the pinion side of fifth gear. I am afraid to hit the pinion shaft too hard as it might deform the driver gear on the end of it.

I forget if there are threads in the end of the shaft. If so, you might thread a bolt into the end of the pinion shaft. Otherwise, use a grinder to cut away the gear. If you're really careful, a 4" Makita or an air powered die grinder (the angle type works best) and a lot of patience will get you where you want to go. BTDT in similar situations. Might want to remove the synchro parts before you start .................

That's an interesting failure. I've seen broken gear bearings and damaged inner races (as well as the gears themselves) caused by lugging. Never that bad, though.

The Cap'n

If the bearing seized, then the inner race would spin on the shaft until it seized too. I'm guessing the shaft is pretty messed up under there. I say weld something to the gear that you can get a puller or a big slide hammer onto and then see what happens. You should be able to mig weld on the outer part of the gear and then quench it before the heat gets to the shaft.

Yeah my customer kept driving and just attributed the extra noise to an old gearbox. Now the pinion gear is pretty trashed. Some of the teeth fell into the lower part of the sump and was picked up and pinched between the ring gear. He is planning on getting another box, just would like to save some parts from this box.