# Lubricating sealed bearings



## Oldmechthings (Jan 28, 2008)

I have devised a pretty slick way (pun intended) of lubricating sealed bearings. It is so simple and non destructive. The bearings are placed in a container just big enough to hold them. In this case, a little plastic cup. Oil is poured over them until they are completely submerged. Normally I use 90W gear oil. Then the cup is placed under the bell jar on the vacuum table, and a vacuum pulled which extracts the air. As you watch you can see the air being pulled out of the bearings and bubbling up through the oil. After a moment or so release the vacuum and oil will be sucked into the bearings to replace the missing air.







I've lubricated lots of bearings this way. Usually they get over filled so they leak a bit until the excess drains out, but that is ok. I've re-lubricated electric motor bearings that sounded like they were wore out. The bearings in my 50 plus year old table saw sounded like a grist mill until I lubed them. Now they are quiet as new ones. One time I ran onto some new-old stock bearings that had set on the shelf so long the grease had hardened rendering them useless. Some fresh oil to soften the grease and and they are ready to roll again.
Not every shop is equipped with a vacuum table and a bell jar, but something as simple as a 1/2 pint canning jar with a hose fitting soldered to the lid would work fine. There are lots of sources for vacuum, some people could even hook it up to their head. A vacuum cleaner would probably not draw enough. You need at least 15 inches. Those hand pumps that are used to bleed hydraulic brakes would work, there are aspirators available. Even condensing of steam in a closed chamber.
Play a little, you will have fun with it.
   Birk


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## b.lindsey (Jan 28, 2008)

Birk

Does the 90W oil reinvigorate the remaining grease in the bearing or actually replace it. If it replaces it, does the process need to be repeated periodically?

Bill


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## georgeseal (Jan 28, 2008)

Birk,
Great idea
I bought a FOOD SAVER jar sealer and if you have a vacuum you are in bussiness

They come in two different sizes small Mason jars and large Mason jars.
After opening paint or varnash I put them into a jar and vacuum out the air. I get good results some poly is over a year old with no film on top.

PS the Food Savers are very expensive but maybe you can get the other half to spring for one. All you need to do is convince them that THEY realy need it.

George from Conyers Ga.


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## Oldmechthings (Jan 28, 2008)

Bill
So far as I know the new oil just juices up the old grease, because the grease does not come out. The 90W is viscous and stays in the bearings a long time. It seems to work fine, sure better than dry ones. Are you aware that wheel bearings on semi trucks and trailers run in gear oil? It must be good stuff because there sure a lot of them on the road.
  Birk


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## b.lindsey (Jan 28, 2008)

Thanks for the additional info. I wasn't aware of the wheel bearings, but am thinking that 90W oil is typical of that used in differentials. The idea is a good one and one i am sure i can put to use from time to time as well.

Bill


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## DICKEYBIRD (Jan 28, 2008)

Oldmechthings  said:
			
		

> There are lots of sources for vacuum, some people could even hook it up to their head.


OK, now you've done it. You're gonna have to come clean the coffee off my keyboard now!

Seriously though, you are a boundless source of knowledge and I appreciate your taking the time to share it with us. Always with a sense of humor too. KEEP IT COMING!

Maybe we need a separate forum heading called "Birk's Brilliance" so all those good tips would be easier to find.


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## Bernd (Jan 28, 2008)

If anybody is interested, I built my own vacuum chamber using a refrigirator compressor and some kitchen Peyrex bowls. Yoy'll find my write here:Vacuum Chamber

Bernd


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## DICKEYBIRD (Jan 28, 2008)

That's great Bernd! Very nice, inexpensive solution.

Now I have to build yet another useful device.


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