Since he is a plant mechanic I know he is somewhat limited on what he has for machines. I don't know if he can cut a key way or not. I guess that this started as a challenge and turned into an experiment. If he can find a cost efficient way to rebuild over replacing these spindles.
I really can't believe that someone hasn't come up with a system to rebuild or replace these. If you figure $150 for a new spindle, if all 3 are bad, you are at $450. how much is a deck really worth? I have not done any measuring to see if any of the new style spindles would fit. add in the out dated blades (odd sized & hard to find) and it may be next to impossible to find a reasonably priced alternative.

Greg

How little of a lathe is he using? What is he using for tooling?

I went through the same thing last month. After cutting the race off, sourcing the bearings, and costing the machine work it ended up close to 500.00. so I trashed that idea.

I did find a guy who has a set of (3) NOS spindle bearings, but he wanted 140 per unit, and like previously said is it worth it? never mind having to find replacements in the future. Trashed that idea.

I did what J-Mech said, I was able to find some of the 48" cast housings. Just know that they aren't the same as the 38/42" decks, and the spindles shafts are different too.
Mike

Not sure of the exact size, but I do know that they turn some large rollers on it. He works in a corrugated cardboard plant so it's not just a little bench top lathe.

Greg