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Discussion Starter · #1 ·
I got my old 8/25 put back together finally, the parts were on the floor of my workshop that got flooded here in BC but luckily (?) nothing was damaged. Replaced the bushings in the gearbox, at the ends of the augers, and filled it up with 00 grease. Auger bushings weren't threaded so I had to tap those.

Confusion started wen I was reassembling the impeller bearing.

The impeller shaft and key and both stepped down where the bearing sits. There's also a notch out of the inner race of the bearing. I'm 99% sure I didn't lose any parts, so it was like this when I took it apart.

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I can't figure out if I'm missing parts, I can't find any diagrams that show this notched race and stepped down shaft arrangement. It seems to me that the notched inner race is unnecessary, if it was just a normal bearing you could maybe locate the notched key in the bearing and get it started on the shaft, then tap it down into place. Or alternatively, if the key wasn't notched you could insert the key into the shaft and then slide the notched bearing down the shaft (and then the key would prevent the inner race from slipping).

But regardless that doesn't explain why the shaft and key are stepped down in the first place? Not sure why a bushing would be necessary there as the key should prevent the bearing from spinning.

It seems like there should have been a split bushing in the stepped down shaft area where the bearing lines up, so I took an old bushing and cut it in half and filed it down until it fit snugly between the bearing and the shaft when the bearing is snugged down.

So much quieter now. No wonder it was clunking so much. This machine has been apart many times so who knows if it was cobbled together out of a few blowers.

Just curious what the "right" way to do this would have been. I'm going to pull it apart again next fall anyway to finish replacing the seals and bushings in the gearbox.
 

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Please allow me an "I told you so" Old Craftsman 8/25 rehab
You've probably guessed that shaft has been worn down by the hardened inner race. Someone here has addressed that issue with welding keys onto the shaft and filling in with metal epoxy. I've shimmed the bearing rearward to get a good seat again. Your solution sounds OK although now your inner race is no longer keyed to the shaft. [not that the key did the shaft any good in your case]
It's a tough situation probably only reliably solved with a new [used] shaft.
 

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Discussion Starter · #3 ·
I could swear the shaft was machined that way but I could be wrong. It's a very even 1/16" groove with 45 degree shoulders and the key isn't welded, the key notch isn't smooth with the shaft notch either. Parts machines seem to come up for sale around here pretty often so I'll probably grab one at some point.

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I'm going to say it was heated and shaved down like a lathe ....... was making a loud racket for sure I imagine ..... :)

Your fix is exactly what I would have done.
 

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Cool picture of the key.
I'll assume you're putting in a new bearing since the old one was spinning on the shaft. Was the old one still turning somewhat freely?
 

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I think the key way on the inner bearing race and key are there to lock the inner bearing race to the shaft and help prevent a seized bearing from wearing down or notching the shaft which looks to be what happened. A locked up bearing probably sheared off the section of the keyway that is missing and continued to do the damage to the shaft. I'm sure the manufacturer of the snow blower felt that the bearing keeper would be sacrificial in the event of a bearing failure as it was cheaper and easier to replace than a drive shaft. Without a key tying the inner race to the shaft your temporary bushing may or may not last long. I would definitely be looking for a new, or good used shaft a new key and a new bearing.
 

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Discussion Starter · #8 ·
I think the key way on the inner bearing race and key are there to lock the inner bearing race to the shaft and help prevent a seized bearing from wearing down or notching the shaft which looks to be what happened. A locked up bearing probably sheared off the section of the keyway that is missing and continued to do the damage to the shaft. I'm sure the manufacturer of the snow blower felt that the bearing keeper would be sacrificial in the event of a bearing failure as it was cheaper and easier to replace than a drive shaft. Without a key tying the inner race to the shaft your temporary bushing may or may not last long. I would definitely be looking for a new, or good used shaft a new key and a new bearing.
Crazy, it must have been locked up for a long time to wear that much. As I said above I'll keep an eye out for a parts machine.

Cool picture of the key.
I'll assume you're putting in a new bearing since the old one was spinning on the shaft. Was the old one still turning somewhat freely?
I popped off the covers and cleaned it out, it's a little noisy but not too much play. I packed it with 00 grease (probably too heavy)
 

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I'd wager that bearing isn't the one that caused that damage. I suspect the original bearing failed and the machine was run a good long time, damaging the key and shaft. The one in the photo is in too good a shape. It is likely a replacement.
 

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None of the Craftsman units I've had have had a bearing with a key slot in them so take this with a grain of salt. I'd say the shaft looks like it was spun alot with a bad bearing, wearing the shaft. I don't see where the OP listed a model number so here's some generic info. Easiest solution would be to find a parts machine and pull the shaft out of that one. The other 2 require some disassembly and machine work. The first of these would be to pull the shaft and have it spray welded then turned back down to final size. The other is have the shaft machined in the damaged area and a piece of copper or steel pipe cut to dimensions, split and JB Welded into the machined area. Once it's dry (the JB Weld), machine it down to the OD of the shaft and the bearing should slide on.
Good luck.
 

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Discussion Starter · #11 ·
Thanks I'll look around for a parts machine. It's a Craftsman C950-52708-0
(Noma? Murray?)

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