10" Spindle bearing mystery.....

So...I have this 10" south bend lathe, and I decided to refurbish the headstock due to lots of play in both directions. Upon disassembly-I found bearing shims under the bearings themselves-as shown in the pictures. I dont understand why someone would shim in this manner-but I am new to this world of precision-so I am asking the good folks her at PM. I thought the shims were to be placed under the bearing caps-to shim the caps up-rather than shimming the BEARINGS up against the spindle. The bearings are the type with the adjusters on top, and they wrap fully around the spindle-they are NOT split. The spindle is the "large" spindle, and it takes the 1 7/8 felt washer (I am also on the hunt for the roller bearing upgrade)in front of the locking collar. Lathe Serial# 4089RKL11

THANKS!!

Perhaps some owner didn't know how to properly adjust the bearing clearances. Does it look like excessive wear on the spindle and bearings?

ElliotKonner said:

The spindle is the "large" spindle, and it takes the 1 7/8 felt washer (I am also on the hunt for the roller bearing upgrade)in front of the locking collar.

THANKS!!

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Such a thing may exist, I'm just not aware of it.

The locking nut side of that spindle cap, typically isn't working hard, so to speak. Yea, the nut and washer hold thrust, but no working weight should be shoving that direction.

The opposite side of that spindle cap, holds the opposite side of thrust, and does see a working load. Which is why there should be a roller bearing there.

The direction of cuts taken. . . Saddle pushes toward chuck, in turn shoving spindle back. Which is why one side has a roller bearing.

Not to say never, but mostly you are not pushing the spindle the opposite way.

Have seen bronze washers with locating pin for that side on ebay though.

Example, but not sure of OD or ID, contact seller for specs:
SOUTH BEND 10L HEAVY 10 REPLACEMENT THRUST WASHER | eBay

As far as shims go. I'd have more questions than answers at first. What do spindle and bearings look like, as SLK001 mentioned. Were there zero shims under the caps ? Expanders and such seem in order ? If no shims under caps, maybe bearings were naturally worn to need replacement, but someone cheated to get more time. Maybe headstock was lined bored or honed to an oversize, those oil drain back holes seem more open/exposed then I would guess, but I'm not familiar with a 10.

As a general rule in regard to shims. I don't know what the last guy did, or was thinking. So I start over without them, gotta set clearances anyway. If you start with zero shims and follow procedures, I'm sure any problems will show themselves.

kind of makes no sense that this is a shell bearing machine with adjusters on top BUT the bearings are not split...


anyhow, those shims are certainly not as manufactured.

Thanks for the helpful replies....as far as the bearings being "split" or not-my bad. I meant to clarify that they were not bearings composed of 2 halves-but they of course must be split in some way to acomodate the adjusters. The surfaces of bearings and the spindle really don't look horrible-however there are "sleeves" that the sprung oil-wicks ride in-and the one closest to the chuck was pressed in so far that one of the oil passages was blocked. I was able to tap this sleeve, thread in a bolt, and pull it back up into correct position. And to answer another question-yes there were shims under the bearing caps in addition to those under the bearing shells-I kept all of them in proper order, and will use them in the reassembly process. Texas-as you stated-without knowing what someone else was thinking-best to start from scratch. Does anyone know the torque specs for bearing caps, or any potential torque LIMIT on the screws for the adjusters? Thank you all again for the replies!

Again I'm not intimate with a 10, but i wouldn't guess a sleeve was not original in wick hole. I cant fathom why that would be bored larger, but if wick seems correct diameter in it, then leave it in, but i might loctite it in upper position.

The cap bolts would be normal bolt torque for whatever size thread it is. 75-80 for 1/2" bolt, 55-ish for 7/16. They aren’t special bolts like a cylinder head might be.

The expanders have a special little procedure. You want to read that before assembly.

Oil clearance on spindle is .00075" to like .001" or .0011 ish.

Spindle end thrust like .0005" to just under .001".