Should I wash the grease out of Myford ML7R headstock bearings?

[Xyphota]

I picked up a ML7R recently and discovered that the previous owner put grease in all the grease fittings. I’ve disassembled the headstock/spindle and found the rear bearings also have grease in them. Thankfully the main bearing/bush has only oil in it.

The manual says both the main bearing/bush and the rear spindle bearings should be oiled with NUTO H32

Should I try to flush the grease out of these? I’ve pulled them out of the headstock already and just wondering what the best way to do so might be. I have access to a high temperature parts washer at work (kinda like a commercial dishwasher) so I could toss them in there which would clean them right out.

 

[DavidR8]

I'm definitely not an expert but I'd clean all the old grease out.
Others with far more experience will be along

 

[Xyphota]

Yeah thats sort of my feelings too haha. The grease in inside the carriage and on the ACME screw threads on the power feed and cross feed is solidified and yucky, but the grease inside these ball bearings is still pretty fresh and oily. I guess my question is what is the safest way to clean out the grease?

 

[DavidR8]

If you’ve pulled them out of the headstock then I’d drop them in some mineral spirits and use a soft brush to clean out the grease.
Dry them off and and them oil them up with the recommended oil.

 

[Former Member]

Yes, and lube it properly. You'll find it should rotate better. As long as the parts washer is solvent based you should be ok.

 

[6.5 Fan]

I'm with David R8, solvent and brush, reoil as per spec.

 

[Susquatch]

I agree with others.

However, my concern is not with what to do properly, it is with why did the previous owner do that?

I think you need to explore that fully and make sure you cover all the bases before just fixing the obvious.

It could be that some part of the oiling system is fudged and grease was the cheapest easiest solution. You need to check all that before assuming anything.

 

[cuslog]

Speculation on my part:
I believe some machines come with what look like grease zerks but on reading the manual, they spec. some kind of oil. I presume one can buy proper oil fittings to pump oil into these ?

 

[Xyphota]

There are zerk fittings so I think cuslog is right and the previous owner just didnt know any better. Fortunately the machine looks to be very low mileage so it was probably pumped full of grease and then it just sat there.

 

[Proxule]

I would wash in varsol / min spirits / paint thinner / toluene / xylene / Anything - Just get that grease out.
SIlver lining..... Previous owner did not know how to properly lube the lathe, But he did indeed lube the lathe.
Better then letting everything run dry.

 

[historicalarms]

My take on this is that the grease in those bearings wont hurt a thing as long as the lathe is in a temp controlled room that is warm enough that the grease wont pull the motor down.
If the lathe has oil journals that require constant oiling (as in "no oil splash sump") during use, I suspect the previous owner decided to use grease as a "less maintenance required" solution.

Grease has been use in bearings that turn much faster, way more load and many-many more hours than a lathe spindle.

 

[Xyphota]

Thanks for input everyone! I chucked them in the parts washer, dunked them in acetone, blew them out and submerged them in oil. I reassembled and set the preload on the bush. Spun up to 2500 RPM and everything felt pretty good. Will try to make some parts tomorrow.

 

[Former Member]

One of my customers educated me on grease. Greases come in different varieties, mix different greases is a very bad thing. The add ins sometimes can work against each other to completely eliminate any lubrication properties , oils can have the same effect, in some cases also interact negatively with the metals used in the bearings (same for greases).

 

[Cryoine]

My take on this is that the grease in those bearings wont hurt a thing as long as the lathe is in a temp controlled room that is warm enough that the grease wont pull the motor down.
If the lathe has oil journals that require constant oiling (as in "no oil splash sump") during use, I suspect the previous owner decided to use grease as a "less maintenance required" solution.

Grease has been use in bearings that turn much faster, way more load and many-many more hours than a lathe spindle.

from what I understand oil is superior to grease in this respect because grease will hold metal chips and dust in 'suspension' acting more like an abrasive than a lubricant. This is also why non detergent oils are used on lathes, that is from my understanding so someone could correct me if I'm understanding this wrong.

 

[phaxtris]

Speculation on my part:
I believe some machines come with what look like grease zerks but on reading the manual, they spec. some kind of oil. I presume one can buy proper oil fittings to pump oil into these ?

There are a few videos online of how to turn a grease gun into an oil gun to pump oil through zerk fittings, basically cap the end off and use it upside down

 

[Tom Kitta]

Just remember that grease is more or less thicker oil. Grease is made with oil as lubricant.