Oil for sealed bearings?

Joined
Nov 9, 2008
Messages
21,322
Location
NH
Sorry, not sure where to put this thread.

I picked up last year a small belt sander, finally getting around to messing with it. Top bearing was gritty, so I drifted it out. I know sealed bearings are more "sealed" than actually sealed so I removed the cover, gave it a brake cleaner bath, and it worked properly. Without thinking about it, I put a bit of 3N1 oil in, which of course means it doesn't spin as freely, but at least it now has oil instead of gunk in it.

I still need to get belts for it, but after doing the work, I realized, I should have done this thing called thinking before using 3N1 oil. What would be a better oil here? or does it not matter, since it's just going to get fine sawdust in it anyhow, and need to periodic cleaning anyways?

1674414777838.jpg
 

supton

Thread starter
Joined
Nov 9, 2008
Messages
21,322
Location
NH
Grease. Pick your favorite flavor/color.
Like wheel bearing grease, marine or otherwise? I thought about that, but the balls are actually hard to get to. Something that drips in would be easier.
 
Joined
Jun 1, 2009
Messages
2,879
Location
Virginia
Like wheel bearing grease, marine or otherwise? I thought about that, but the balls are actually hard to get to. Something that drips in would be easier.
If you're starting from a blank slate on a little bearing that isn't submerged in water and isn't mission critical to anything it really doesn't matter that much and you can use just about any grease you want because you don't have to worry about mixing incompatible greases.

You don't have to (and generally shouldn't) fill them completely up either. It probably came from the factory ~1/3 to 1/2 full of the cheapest lithium grease they could source.

Just realized I have that exact same sander.
 

supton

Thread starter
Joined
Nov 9, 2008
Messages
21,322
Location
NH
If you're starting from a blank slate on a little bearing that isn't submerged in water and isn't mission critical to anything it really doesn't matter that much and you can use just about any grease you want because you don't have to worry about mixing incompatible greases.

You don't have to (and generally shouldn't) fill them completely up either. It probably came from the factory ~1/3 to 1/2 full of the cheapest lithium grease they could source.

Just realized I have that exact same sander.
Not sure what was in there--some brown stuff came out when I hit it with brake cleaner, then it worked properly. No idea, prior user gave it a good using.

Ok, when I think of doing this again, might do marine wheel bearing grease, if it doesn't work, it'll clean out nicely (not sure if white lithium will or won't, but by the time I need to do it a third time, my bet is that I'll be ready for some newer sander).

If you have the same model, it wasn't a bad job, I popped off the belt, then took off the snap ring, then loosened the allen holding down the shaft that the top pulley is on. Pulled it out, then drifted out the spindle, then drifted the rubber wheel off. I don't think you have to remove the spindle... but having it out of the way will likely make it easier to remove the dust shield, as it's metal, not plastic (at least on mine). I had to use an old heavy duty knife so as to get a rugged enough yet thin enough point to get in there to pry it out.

I haven't tackled the lower pulley yet, that looks more complicated, as it has the spring on it for tension and tracking.
 
Joined
Apr 6, 2015
Messages
1,439
Location
Upper midwest
A lot of high quality Japanese bearings use Mobil 1 Electric Motor Polyrex EM grease. Cheap enough to buy a tube. At work I always add a small percentage of this grease if it is the same blue color as I find there just is not enough grease these days in new bearings for long term bearing use like years ago. Seems like planned obsolescence at play to me. We have better long term outcome doing this on a problematic machine that has an under sized bearing that gets abused. I flush out and repack with this grease and leave space for expansion then reseal with original seals.

 
Joined
Jul 15, 2018
Messages
1,087
Location
illinois, usa

Corrosion Technologies 77001 SpeedX 1 oz. Bottle​

Look into this product

  • Precision instruments and gears
  • In-line Skates
  • Skateboards
  • Slot cars
  • Bicycle Gears, Chains and Bearings
 

supton

Thread starter
Joined
Nov 9, 2008
Messages
21,322
Location
NH
Bearing in question: 6202Z.

Found a cutaway pic of the bearing. I guess I could work grease into it? Work it in with my thumb.

1674428162398.jpg


Corrosion Technologies 77001 SpeedX 1 oz. Bottle​

Look into this product
That looks like a better fit, thanks. Will add that to my Amazon cart and think about that, there's a number of "sealed" bearings around the house.
1674428311475.jpg
 
Joined
Jul 15, 2018
Messages
1,087
Location
illinois, usa
Bearing in question: 6202Z.

Found a cutaway pic of the bearing. I guess I could work grease into it? Work it in with my thumb.

View attachment 136755


That looks like a better fit, thanks. Will add that to my Amazon cart and think about that, there's a number of "sealed" bearings around the house.
View attachment 136756
You can also used it on the bearings from a furnace draft inducer motor, one more application.
 
Top