A silly grease question

[NYCone]

I just bought three old Metabo Angle Grinders on eBay. They've seen heavy use, but are basically OK. I wanted to clean them up a bit and repack the gears with grease.

The Metabo grease is crazy expensive, like $160/lbs. Its a clearish synthetic grease. I don't know enough about different greases to know if there's a cheaper version (Super Lube?), or if any old grease will do.

Please bear with my lack of grease expertise. What is best practice without buying the Metabo $160 grease.

 

[kelpaso1]

I've always used cv-joint grease in the ones I've repaired. No problems for years that I'm aware of.

 

[Sumboodie]

I've just used whatever was in the grease gun.

 

[dogdog]

Moly grease is what I try to use....

 

[NYCone]

Thanks

 

[kelpaso1]

Moly grease is what I try to use....

Which is usually what cv grease is.

 

[KnurledNut]

For those interested, some OEMs use Rheolube 380-G1 by Nye Lubricants.
This is more of just factual info than a recommendation, as its hard to source and expensive.
But i doubt you’d find a better engineered grease for the application.

Here is the spec sheet:
https://www.nyelubricants.com/stuff/contentmgr/files/1/f2905a34163b456dade58fda52cdbd14/en/product_overview___rheolube_380_380_g1__nye_lubricants_.pdf
https://www.endo.com.tr/extras/dosya-merkezi/REDUKTORLER/APEX%20DYNAMICS/Kalite%20Belgeleri/Nye%20Nyogel%20380G1.pdf

 

[bob15]

Why not e-mail Metabo and ask them what they use? Or what they recommend.....

 

[Shiftless]

Why not e-mail Metabo and ask them what they use? Or what they recommend.....

I thinks it’s safe to say that Metabo will recommend their own $160/pound grease.
Besides the color, I can’t see why it would be superior to Mobil 1. The red stuff.
Having clear grease might be nice if it leaked. It wouldn’t stain. But the red Mobil One doesn’t seem to stain my fingers when I smear it on something.

 

[dogdog]

Which is usually what cv grease is.

Yes it is, but usually CV grease is more expensive Not sure why

 

[rlitman]

Yes it is, but usually CV grease is more expensive Not sure why

Because CV grease isn't plain moly grease. It has sulfur based additives, just like gear oil, hence the godawful smell. Moly grease is good for sliding metal on metal low speed wear, but there are better choices for high speed metal on metal sliding as found in hypoid gears (as found in better grinders, as an improvement on crown gears).

I haven't re-greased any of my grinders yet (they haven't seen enough hours), but I really like the CV grease idea. And I happen to have an extra packet of it sitting around that came with a CV boot I used for a non-automotive purpose (replacement air bellows on my scroll saw). Now I know why I've been saving the stuff.

 

[neophyte]

I thinks it’s safe to say that Metabo will recommend their own $160/pound grease.
Besides the color, I can’t see why it would be superior to Mobil 1. The red stuff.
Having clear grease might be nice if it leaked. It wouldn’t stain. But the red Mobil One doesn’t seem to stain my fingers when I smear it on something.

Trumpf is one of the main manufacturers of sheet metal shears and nibblers in Europe.
They also manufacture shear and nibbler heads for a number of other manufacturers.
Nowadays they just recommend their own grease( actually two separate greases for different areas of the tool) for lubricating their tools.
In the past though, some of the manuals listed alternative greases that could be used.
They were very explicit about the manufacturers and grease formulation numbers.
I once checked into the alternative greases, and all of them were somewhat obscure and expensive.

Also, the grease spec’d by most power tool manufacturers is usually expensive, even from a company like Dewalt.
I wouldn’t be surprised if Black & Decker realized that quality grease was an area they couldn’t cheap out on.


Flex at one point must of found performance issues with the grease used in one of their polishers.
I recall they not only changed the grease specified, they also had to change a couple other pieces of the grinder.

 

[neophyte]

I should probably add, if you want to use a “cheaper” grease, maybe buy a tube of the grease Fein uses in their angle grinders.
https://www.ereplacementparts.com/tube-grease-p-220450.html
It may be just as expensive per quantity as the Metabo grease, but it’s available in smaller tubes, rather than a larger tub.
You would want to thoroughly clean out all the old grease, since some greases are non compatible with each other.

 

[NYCone]

Well, I couldn't wait anymore, so I sealed back up my grinder with some Stay-Plex red grease I had laying around.

I don't think it's the best option, but it was free (I had it already) and will work well enough for now.

As I said before, I have no grease expertise, so if I've done something foolish, feel free to let me know.

 

[rlitman]

Well, I couldn't wait anymore, so I sealed back up my grinder with some Stay-Plex red grease I had laying around.

I don't think it's the best option, but it was free (I had it already) and will work well enough for now.

As I said before, I have no grease expertise, so if I've done something foolish, feel free to let me know.

I'm sure it will be fine. In terms of grease, any grease is better than nothing, and your choice was an excellent grease.

The only risks you have in re-greasing are using too much, and incompatibility. And so long as you removed the grease that was already in there, incompatibility will not be a problem.

 

[John T]

John Deere corn head grease would work great in that application.

 

[theoldwizard1]

Thread from the long dead !

Most power tool grease is white lithium. Pretty cheap stuff. Most of it gets thrown off of the gears anyway. If it is not to nasty looking, I just scrape it fro the outer part of the case and apply it to the gears.

 

[cjarvis]

I use Lubriplate GR-132 Portable Tool Grease.

https://www.lubriplate.com/Consumer/Consumer-Products/List/?categoryname=GR-132_1

LUBRIPLATE GR-132 is being used very successfully in a wide variety of applications includingortable electric tool gear cases, Fractional horsepower gear cases, High speed ball and roller bearing applications such as found in grinders, woodworking machinery, exhaust fans, blowers and high-speedmixers, Gear cases of mechanical bunny (Dog Tracks), Hi-cycle rotor grinders and tools.

 

[bob15]

Thread from the long dead !

Most power tool grease is white lithium. Pretty cheap stuff. Most of it gets thrown off of the gears anyway. If it is not to nasty looking, I just scrape it fro the outer part of the case and apply it to the gears.

This tread was started 2 days ago.

 

[John T]

What is “Silly grease?”

 

[Djosbun]

I've got full cartridges of PFPE/PTFE grease (just like Dupont Krytox GPL) that I sell to a few select customers for about $100 cheaper (800 g) than the price of Krytox. It's used in critical applications (F1 wheel bearing assemblies, for example).

-- Dave

 

[neophyte]

What is “Silly grease?”

Silicone presumably.

 

[Garage-ist 2]

cjarvis: Appreciate the link to the Lubriplate.

Great info all around.

 

[rlitman]

I've got full cartridges of PFPE/PTFE grease (just like Dupont Krytox GPL) that I sell to a few select customers for about $100 cheaper (800 g) than the price of Krytox. It's used in critical applications (F1 wheel bearing assemblies, for example).

-- Dave

Krytox would be great in a grinder gearbox. But if you're paying retail prices for it, the grease would challenge (and possibly exceed) the cost of the grinder.

I just opened up a 15g tube of the stuff yesterday (GPL 105) at work for a specific project (a robot with a stick-slip chatter issue). Yes, PFPE has specialized uses, like the space station arm and Swiss watch movements, but it also has more mundane uses, like lubricating the seals on sunroofs and o-rings on commercial coffee makers, though the biggest commercial use is in cardboard manufacturing.

I've got a 14oz cartridge (400g) of Krytox (GPL226) that I got on eBay for $65. Still haven't opened that one yet.

 

[Djosbun]

Once in a while I see really good prices on Amazon for different grades of GPL but typically stuff I have no use for due to its viscosity (and being suspect of the seller). You are correct about automotive seals, as it's used by almost all major manufacturers on rubber sealing surfaces. I have sold tiny bottles (2 oz) to firearm manufacturers as well. Klueber also offers a few different options of PFPE grease, Barrierta being their long-standing product. Last time I checked it was about $1000 per pound.

-- Dave

 

[tool_scrounge]

While not stated, I presume most folks know to completely clean out the old unknown grease before adding a new one. The thickeners in greases can often not be compatible with different types.