Grease for lathe bearings?

[Wilbur Pan]

I have an old Walker Turner lathe that I'm fixing up. I have the headstock disassembled. The bearings seem stiff, but I think that may be because the lathe pretty much sat unused for ~10 years before I bought it. The old hard grease that I've dug out of the headstock so far certainly doesn't look like it's doing much in the way of lubrication -- it had the consistency of earwax.

I plan on using naphtha to try to dissolve/clean out the old grease, then repack the bearings. I'd get new bearings, but these seem to be a nonstandard size, and I haven't found them to be available anywhere yet.

My question is, is there a recommended type of grease for lathe bearings? I'm most familiar with a white synthetic grease that I use for the wheel bearings on my bicycle, but I don't know if that would be suitable for a lathe.

[Keith Burns]

I would take the bearings to a Bearing Supply House. I would bet they could match them up. If they have set for 10 years they are probably shot anyway.

[John Hart]

Keith's probably right...but if you do try to repack them....only pack them half way, as a full pack will cause stress and put an unnecessary load on the motor. Molybdenum Disulfide Lithium based grease is good stuff....found at automotive stores.

[Christopher Zona]

I would suggest NSK, NTN, GMB, FAG or Timken bearings as replacemnets. As for grease, try to chase down some Kluber Asonic AHQS which NSK uses. We use all of the above bearings for automotive applications.

[Bill Boehme]

What has happened is that the oil has separated from the soap and the soap is all that is left in the bearing.

I can't say which type of grease would be best for your lathe, but I know that Baldor uses Exxon Mobil Polyrex EM grease for all of their industrial motor bearings. Automotive wheel bearing grease may not be the best thing because the load and temperature requirements are considerably different than that of your lathe.

John Hart is correct about packing -- over packing increases the hydraulic pressure tremendously and is as bad as letting them run too low. Also, never mix greases. The soap used in one grease is not the same as that used in another and there is liable to be a breakdown of the lubricant from doing this. If you do not know what grease was used before then use naphtha to degrease the bearings and start with a fresh fill.

Bill

[Gary DeWitt]

I recall from auto shop (ca 1970) that you never use solvents to clean a bearing, as it's very difficult to get all of it back out of the bearing before repacking it. The trapped solvent breaks down the new grease and the bearing eventually siezes.
Don't know what you do clean them with. On auto bearings, we would just pack enough new grease to push out the old grease and the dirt with it.
Easier and in the long run cheaper to get new ones, I suspect.

[Bart Leetch]

If they are Timken bearings use high temp automotive wheel bearing grease that is what I have in my 1930's Delta double duty lathe & it has worked fine for the last 5 years that I've had it. Check the bearings just like the were automotive bearings if they look ok pack them & run them.

[Paul Engle]

Wilbur,
I would suggest taking the brg to a brg supply house / as you may want to consider switching to a sealed bearing. Most newer automotive brgs are sealed now a days which solves a few problems, if not the brg guys would know which grease to use , as newer disc brakes became common a newer grease was developed to address the heat from constant rubbing of the disc by the caliper , the heat got transfered to the spindle and on to the bearing. Oil bath is good but hard to do ( like the manual transmission) bearings really only need small amount of lubrication as the point of contact is very small, the grease was used to keep out dirt etc and get away from oil bath type lube, ( hard to have oil bath on front wheels of a car, mess to install and a pain to service every other oil change) rail engines use/d an oil bath also. You may check with the spindle on the frame to see how the thrust was adjusted for, don't want a bearing that will let the spindle slide back an forth. Some ( like metal lathes) use a combination brg that acts as radial load( vertical) and radial load ( horizontial , thrust type) older ones are typically oil bath ( the good ones)some can be shimed to a " 0" preload or up to say up to 5 lbs of preload to accomidate wear and heat rise ( seen in oil bath brgs as the oil keeps the heat down but no slop is the result). Rule of thumb on ball bearings is loose is better than too tight, ask a mechanic about doing the brg play on semi truck wheel brg they also use oil bath.

[Christopher Zona]

Wilbur,

If it is grease for hubs then it should handle the load of a work piece just fine. RPMs and temperature aren't a concern, since bearings for lathes can probably safely handle 9000-13000 rpm and the ambient temperature of the lathe will probably never see -30°C or 140°C, which most bearings are designed to handle.

Just be sure to help keep as much contamination out as possible. This is what kills any grease. Since the balls or rollers float on the grease, contamination will cause the grease to shear and allow the balls to contact the raceways. This is just one of a couple dozen other ways that a bearing can fail.

Also, when re-installing, if your bearings are press fit into the head, be sure to only press on the race that has the press fit, i.e. outer race to headstock or inner to spindle/shaft. Reversing this can cause accidental galling on the races. Slip fits shouldn't be a problem.

"The Lathe Book" by Ernie Conover has a pictorial layout of one way to remove and re-install bearings.

Good luck.

[Wilbur Pan]

Thanks for the suggestions. Soaking the bearings in naphtha cleaned out all the old grease and gunk, and they seemed to spin much more freely. I packed the bearings with automobile bearing grease, and reassembled my headstock. All seems well at this point.:D