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Do I need to Replace my Bearings?

Posted: Sun May 05, 2019 3:02 am
by Chriss
A few months ago I started pulling apart the 10ER my grandpa gave me. You guys gave me some good advice and help with that. Thanks. I've been on hold for a while, but got back at cleaning it up this weekend. The quill, drive splines, bearings, pinion, etc. were all pretty gummed up with some sticky thick grease. It's been a good 15-20 years since the thing has been used, so I guess I'm not surprised by the condition.

The drive sleeve bearings turn smoothly, but don't spin freely. They are fairly tight feeling, like they are packed with old gummed up grease. The quill bearings barely turned until I dipped them briefly in mineral spirits and gave them a couple rotations. After that, they spin really easily. I can give the shaft a good spin, and it'll keep spinning for a bit. But, the bearings sound kind of dry to me.

I'm no expert on bearings. I figure dipping the quill bearings in mineral spirits wasn't that good for them. But they weren't doing me any good in the condition they were in, so I figured I had nothing to loose. I have not dipped the drive sleeve bearings yet.

So, my question is how do I know if I need new bearings? I'm thinking since I have it apart, I might as well replace them. But I don't want to do it if I don't need to.

The quill bearings on there now are FAFNIR 202KLL3. I'm not sure what the drive sleeve bearings are. I haven't gotten them off yet as I don't have a bearing puller, and the P/N isn't on the side I can see. They do say FAFNIR on the side I can see though, so presumably they are 205KLL2 but I have not yet confirmed.

Anyway, any advise would be greatly appreciated. Thanks.

Chris

Re: Do I need to Replace my Bearings?

Posted: Sun May 05, 2019 1:09 pm
by JPG
Ball bearings are NOT supposed to 'spin freely'.

Rotate easily, but not spin.

There should be some grease in them that causes them to be somewhat viscous.

IF they 'spin freely', the grease has disappeared.

Yes that grease can get gummed up as you described.

IIWM, I would go forward and NOT replace any of those bearings until they indicate they need replacing. Rough, noisey, sloppy.

Re: Do I need to Replace my Bearings?

Posted: Sun May 05, 2019 2:02 pm
by rpd
This link will take you to a post by robinson46176 on how you can re grease dry bearings.
https://www.shopsmith.com/ss_forum/view ... 57#p104257

Re: Do I need to Replace my Bearings?

Posted: Sun May 05, 2019 4:15 pm
by Chriss
JPG wrote:Ball bearings are NOT supposed to 'spin freely'.

Rotate easily, but not spin.

There should be some grease in them that causes them to be somewhat viscous.

IF they 'spin freely', the grease has disappeared.

Yes that grease can get gummed up as you described.

IIWM, I would go forward and NOT replace any of those bearings until they indicate they need replacing. Rough, noisey, sloppy.
So while it is obviously not good to run with dry bearings that spin freely, your recommendation is to just go with it for now till the bearings need replacement? That certainly is the easier option for now and would get the shopsmith running again quicker.

rpd wrote:This link will take you to a post by robinson46176 on how you can re grease dry bearings.
https://www.shopsmith.com/ss_forum/view ... 57#p104257
Ron, I took a look at that post. Looks like a pretty simple option for regressing the bearings. I'm not familiar with electric motor grease. Anyone have any recommendations on what/where to buy? About the only thing I have here at home is wheel bearing grease.

Chris

Re: Do I need to Replace my Bearings?

Posted: Sun May 05, 2019 8:56 pm
by jsburger
Chriss, just replace the bearings. They are are not that expensive. You have the machine apart so do it now. 60 year old bearings (even Fafnir) probably should be replaced regardless "how they feel". I always replace the bearings in the 10ER's I overhaul. That is including the motor.

Re: Do I need to Replace my Bearings?

Posted: Sun May 05, 2019 8:59 pm
by BuckeyeDennis
I reconditioned a radial arm saw motor bearing a while back using that technique, and it worked out well. When I researched electric motor grease, Mobil Polyrex EM was generally touted as the primo stuff. A tube is about $9 at Amazon.

https://www.amazon.com/Mobil-Polyrex-El ... B017WKDTSA

Re: Do I need to Replace my Bearings?

Posted: Mon May 06, 2019 2:49 am
by Chriss
jsburger wrote:Chriss, just replace the bearings. They are are not that expensive. You have the machine apart so do it now. 60 year old bearings (even Fafnir) probably should be replaced regardless "how they feel". I always replace the bearings in the 10ER's I overhaul. That is including the motor.
Any suggestions on where to get the bearings? In my searches, what I've seen looks like it would cost me upwards of $100 or more for the two quill and 2 drive sleeve bearings. And After reading Everett's bearing guide, I'm confused as to exactly what I need. I know the two part numbers, but I'm a little confused on the precision (C1 vs C0, etc). Most sources I've found do not say anything about the precision. So this is partly why I was thinking of trying the repack.

Chris

Re: Do I need to Replace my Bearings?

Posted: Mon May 06, 2019 2:51 am
by Chriss
BuckeyeDennis wrote:I reconditioned a radial arm saw motor bearing a while back using that technique, and it worked out well. When I researched electric motor grease, Mobil Polyrex EM was generally touted as the primo stuff. A tube is about $9 at Amazon.

https://www.amazon.com/Mobil-Polyrex-El ... B017WKDTSA
Thanks for the recommendation. I saw that one when I was looking earlier today. Haven't decided if I'm going to give that a try or buy new ones. But I'll keep this in mind.

Chris