Grease for repacking a new sealed bearing?

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I repack bearings at work 90% of the time. I work for a med sized printer. I use a combo of Mobil 1 Polyurea and Schaeffer's 714 Aluminum Complex. I use just Polyurea on some, both in a cocktail and just #714 depending on speed and bearing load. Clay based greased bearings I leave as OEM filled. I DO NOT let anything Lithium in the building for the last 8 years. Even though they are rated as non compatible I have not had an issue I can see. Even Schaeffer's says you need to test the grease compatibility chart in some cases has very large wiggle room. I found the two that work good together.

As far as the above bearing it is packed way too much. I agree with the poster who commented 1/3 less, but that could be pushed to 1/4 less then the picture.You have to have room for grease expansion and grease push away in the bearing travel path. I spin up all my bearings and side load them with a 1/2 drill on #2 speed, with the nose nips extended. Then I clean the grease IF it comes out of the seal. I use a razor blade and take the edge off on sandpaper or cement. Or lately I use a micro flat bladed screwdriver in the inside part of the seal. You get good at popping the seals out with minimal distortion with practice. My bearing now last a lot longer, close to double on high use heavy loaded bearings and some would still be going now even with low use machines with OEM grease amounts. I see it is worth doing this on most all bearing we use.
 
Originally Posted by A_User55555
I'm all for repacking bearings, but the problem I have is when I remove the existing seal, It gets deformed just enough to have the new grease seep out.

If I could buy bearing seals, I would try and repack them


I don't see this as a problem after using 10 bearings as a seal popping trainer session. After practice you don't do much if any damage to the seals.
 
Originally Posted by Mainia
I repack bearings at work 90% of the time. I work for a med sized printer. I use a combo of Mobil 1 Polyurea and Schaeffer's 714 Aluminum Complex. I use just Polyurea on some, both in a cocktail and just #714 depending on speed and bearing load. Clay based greased bearings I leave as OEM filled. I DO NOT let anything Lithium in the building for the last 8 years. Even though they are rated as non compatible I have not had an issue I can see. Even Schaeffer's says you need to test the grease compatibility chart in some cases has very large wiggle room. I found the two that work good together.

I always thought polyurea grease is the red-headed [censored] child of the greases - loved by motor makers for its low noise and long life and the Japanese OEMs are a fan of it for high-temp and water resistance but it's the least compatible of the greases.

And isn't Mobil 1 Grease a lithium complex product? Unless you're referring to Mobil Polyrex EM which is a polyurea grease. As I understand from that chart, it's OK to mix lithium complex greases with most other greases, WD-40 was touting that ability with their True Multi-Purpose Grease that's calcium sulfonate based with their Li-complex ones.
 
Originally Posted by tom slick
If its a quality bearing it has the proper grease in it. You'd be surprised how little grease is the proper amount.
I'll let Kestas give you the specifics, he's a bearing engineer.

If some is good, lots is better. Sure road to bearing failure.
 
Originally Posted by Dave9
Originally Posted by Kemanorel
As for the comments about grease mixability, yes it is true that white lithium grease will cause all sorts of problems with sodium-based greases, but if you're using something like Mobil 1 synthetic grease then you shouldn't have to worry, right?


No, not right. M1 synthetic is in no way some kind of compatible-with-everything grease.

Repack bearings when you can get new seals (those designed to be serviced). Replace bearings when you can't, or if they are inexpensive enough (from a major brand) that it's not worth the bother.

FYI your picture of the bearing packed with M1 had WAY too much grease in it. Try using about 1/3rd that much.


Bearings should be packed by grease mass. Totally agree not to overfill due to expansion, separation, thermal, etc.

But excess visible isn't necessarily overfilled. Here's a bearing I did by hand, specifically filled by mass in terms of what amount goes in the inner, outer bearings and the cap.

33AE73AB-7DF9-42E7-9A7B-CB1B7B76C067.jpeg
 
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