Those gears are junk. I guarantee it. It's obvious now that it wasn't a bearing making the noise. The noise was coming from the gears. All that silvery stuff that came out was from the gears.
When a pinion gear turns against a ring gear there is a certain amount of deflection. In your case, because the bearing support was sheared right off, there was a lot of deflection. That caused the ring and pinion gears to mesh in a manner they were never meant to see.
Replace the gears or, best case, you will get noise and premature wear. Worst case, sheared teeth. Both of which will ruin your true track and new bearings either from metal shavings or chunks of teeth. You are wasting time, money and effort by not replacing the gears.
I would use the housing a with a proper cleaning and a chunk of magnet stuck to the bottom of the inside to catch any more metal shavings. Or, cheap solution, swap in another axle with matching gears. Or, upgrade solution, swap in a larger axle.