Grease for Mag drill gearbox

[Iron Beaver]

Today I peeked inside the gearbox of my Nitto Kohki mag drill to find a horrid black goo with limited lubrication powers instead of grease. The gears are still in good shape but I think it's time for some new grease. What do y'all recommend? I assume it's not that much different than other power tool grease but I want this mag drill to last a good long while yet. I'm also willing to spend the money for good quality lubrication.

 

[BukitCase]

I'd flush it out at least a couple times with diesel, kerosene, ****** flush, whatever will dissolve the crud - once it's clean, this

Amazon.com

is what I use for any high pressure gearing, ESPECIALLY if worm gears/brass or bronze are there - it's full synthetic and compatible with non-ferrous. A lot of the more common gear lube is NOT good for brass/bronze, the sulphur will shorten their life.

I bought the above to use on all 3 horizontal band saws, my Hougen 917 mag drill, and eventually will clean out all 9 or 10 of my 4-1/2" grinders and lube with it too... Steve

 

[Iron Beaver]

There are no worm gears, only helical spur gears and I think everything is steel.
The plan is to dismantle the whole thing, clean it up with a parts washer (If I can find one), and add appropriate lubricative goop. Something that won't attack the seals or leak all over the place, whatever that is. The current stuff also has it's share of sparkles, so it's really time for a change.

The stuff you linked above looks hopeful

 

[neophyte]

Today I peeked inside the gearbox of my Nitto Kohki mag drill to find a horrid black goo with limited lubrication powers instead of grease. The gears are still in good shape but I think it's time for some new grease. What do y'all recommend? I assume it's not that much different than other power tool grease but I want this mag drill to last a good long while yet. I'm also willing to spend the money for good quality lubrication.

Have you used the drill extensively?
or did you purchase it used, and in its previous life, might the drill have bern used extensively?

I simply ask, because Molybdenum disulfide grease is routinely used in tool gear housings, since the Molybdenum disulfide in the grease can continue lubricating, even if most or all of the oil in the grease separates and leaks out,
And Molybdenum disulfide grease tends to be a dark gray or black color.

 

[kelpaso1]

I've always used the black CV joint grease which is the same that Neophyte mentions.

 

[Iron Beaver]

I bought it used on eBay from (I think) a pawnshop. It shows signs of pretty heavy use, lots of scratches and dings, missing accessories and a few missing non-essential pieces, etc.

The molybdenum disulfide grease I have is a very dark purpilsh blue. The grease in this is jet black. I think it is moly grease but looks like it's seen some miles.

 

[matt_i]

I see SuperLube makes a NLGI #0 grease synthetic w PTFE, I might try that.

Go-to for general tough situations is Mobil XHP222 Special which has the MoS2 however is almost guaranteed to be too thick at a #2 consistency.

If you are positive its exclusively steel-on-steel you can use an -EP grease. Mobilux EP-0 would be perfect but not available in ~14oz tubes.

If this is Chevron Delo EP-0 then I think a reasonable choice.

Amazon.com: Chevron Ultra-Duty Grease EP NGLI 0 (1 Cartridge) : Automotive

Amazon.com: Chevron Ultra-Duty Grease EP NGLI 0 (1 Cartridge) : Automotive

www.amazon.com

 

[Zewnten]

Stock grease for these gear boxes is usually 00 grease. Never been sure how it's supposed to lubricate as it never seems to actually touch the gears

 

[Iron Beaver]

What is this 00 grease, #2 grease, and #0 grease of which you speak? The stuff in there now does not drip but it's not gooey and tacky like the grease I have on hand.

If I ruin this gearbox replacing the drill would cost $4000 so I'm motivated to get it right.

 

[KnurledNut]

Is it planetary or single gear reduction? A pic would be great.

 

[mike93lx]

What is this 00 grease, #2 grease, and #0 grease of which you speak? The stuff in there now does not drip but it's not gooey and tacky like the grease I have on hand.

If I ruin this gearbox replacing the drill would cost $4000 so I'm motivated to get it right.

$4k for a mag drill?

We need pics for sure

 

[neophyte]

Maybe call up Nitto, and see if they have a part number for the grease, or will tell you the specific type of grease.
Sometimes the grease costs $50, but you never know whether the grease was custom for the tool, or some really weird specific grease type.

 

[dscheidt]

What is this 00 grease, #2 grease, and #0 grease of which you speak? The stuff in there now does not drip but it's not gooey and tacky like the grease I have on hand.

If I ruin this gearbox replacing the drill would cost $4000 so I'm motivated to get it right.

Numbers refer to the consistency of the grease. Higher numbers are harder. the ngli scale runs from 000 to 6. Most common wheel bearing etc greases are #2. 000 grease is a bit runnier than ketchup, #6 greases can be used as a soft hammer (at room temperature). Stuff in machine gearboxes tends towards 0 or 00.

That's completely separate from how sticky it is, what the base is made of, what the viscosity of the oil in it is, and the additives.

I second the recomendation to ask the manufacturer. Overpaying for grease is better than buying a replacement $4k drill....

 

[ZRX61]

Maybe Lubriplate, it has a ability to go back into teeth after it gets squeezed out.

 

[Iron Beaver]

It's not epicyclic, just a regular 2 speed gearbox. I'm planning to contact NK to see if they get back to me or not and what they say

 

[Iron Beaver]

Just heard back from Nitto Kohki. They recommend Mobil Mobilith SHC 100 grease for all their magnetic drill gearboxes, so I will be using some. I just picked up a Vessel #2 JIS screwdriver as well.

Mobilith Mobil SHC 100 Single 13.4 oz Cartridge: Amazon.com: Industrial & Scientific

Mobilith Mobil SHC 100 Single 13.4 oz Cartridge: Amazon.com: Industrial & Scientific

www.amazon.com

 

[KnurledNut]

Thanks for the info.
Interesting recommendation.
Lithium complex.

“Mobilith SHC 100 is an antiwear and extreme pressure grease primarily recommended for higher speed applications such as electric motors, where reduced friction, low wear and long service life are required. It is an NLGI 2 Grade / ISO VG 100 grease with a synthetic base fluid. Its operating temperature range is -40º C* to 150º C.”