3 Jaw Chuck Grease

[itsme_Bernie]

Hey Folks
A beautiful Cushman 6 inch 3 jaw chuck that came with this Heavy Ten I got last week.

It's a little stiff, and the previous owner mentioned it could probably use a rebuild, so today is the day. I have some pics below of the disassembly. It is a much nicer chuck than I have owned, as it came apart a totally different way than the "semi-steel" chucks I am used to! Hah hah

I DIGRESS-

It has a factory grease fitting on top.
(EDIT- I found out after writing this that it MAY be an oil Zerk fitting)

Can I use the same PTFE/Teflon grease I would use in my backgear/cone pulley? I have heard of "chuck grease", but don't know if it is different at all.

I want to reassemble it packed already, and also want have the right stuff on hand to keep it up. It sure would help if I could just keep one grease gun at the lathe for everything.

Thanks folks!


Bernie


Grease fitting




When I finally found the seam, I really had to rap hard with this little brass hammer through the rag to split it:




I never had a chuck that split in the middle like this! Very tight tolerance... I could barely see the seam:



I should have shown the dirty scroll and parts first!! But I got too carried away. Suffice it to say, despite this being a well cared for and visually "clean" and high quality chuck, it was dirty, gunky, with hardened grease inside. Only some small brass swarf on the scroll:

 

[Bill Gruby]

These people have what you seek. Pricey though.

http://brassandtool.com/Chucks-Lathe.html

"Billy G"

 

[itsme_Bernie]

I am at Grainger now, and having a mother of a time finding it. The only PTFE grease they have here is Tri Flow Food Grade PTFE ... I have read Permatex 82325 but can't see it here. Dangit

 

[itsme_Bernie]

Also two LPS greases- "DETEX". And "White Lithium with PTFE" ... Can I get a terribly 'wrong' grease for the spindle and chick here? They are really nice and I want to treat them right.

 

[Chuck K]

I've never seen a chuck with a grease fitting. You sure that's a factory item?

 

[itsme_Bernie]

I've never seen a chuck with a grease fitting. You sure that's a factory item?

Sure is Chuck! If you take a look at the pic up there you'll see it is actually pretty nicely done.

BUT- upon further investigation (on Practical Machinist and other sites), and to confuse things more, I have seen some people talk about Zerk (grease) fittings that DON'T take OIL not GREASE.

Other folks say not to oil a grease fitting on a chuck because it will throw a load of oil everywhere.

Again others say no grease even if it asked for because it attracts chips to the nether regions of your chuck. AAAAAHHH!! Hah hah hah.

SO I am going to make a judgement call and let you know how it works for me.
Since this is a very nice chuck, tight tolerances, I am going to SUPERLUBE the gears below the scroll, and OIL the scroll itself.

Grease where it needs it, and it will stay put. And oil where chips will be floating around.

Ok- here goes...

Bernie

 

[itsme_Bernie]

Here are the parts all clean and ready to go back together





The top and bottom halves were a tight fit. There is a tight tolerance in a 2 inch boss inside, where the ends of the bevel gears below the scroll are seated. So I tightened the six (three inner and three outer) bolts in a circular pattern (like one would use a star pattern to tighten lugnuts)




Kept tightening- you can see the gap. The scroll was a close slip fit as well:





There were matching numbers on the main pieces with tolerance fits. Wow, nice chuck! Backplate installed too:




I hadn't noticed when it was grimy that the backplate is original South Bend! Is this Cushman Chuck possibly from the factory?

 

[Sandro]

In 30 years I've never seen a chuck that had a grease fitting. My first thought is to not grease the chuck, just clean it and re-assemble.

Sandro Di Filippo

 

[itsme_Bernie]

In 30 years I've never seen a chuck that had a grease fitting. My first thought is to not grease the chuck, just clean it and re-assemble.

Sandro Di Filippo

Thanks Sandro

I read elsewhere that it may be an Oil Zerk fitting. Meaning, I should put some Vactra or something in a gun with a Zerk and squirt it in.

I have already put grease in the bottom half of the chuck, which in the case of this chuck is pretty tightly sealed. I oiled the top, scroll, and jaws.

I'm sure, over time, the oil will make it to the inside anyway.


Bernie

 

[Tony Wells]

I have seen chucks with lube fittings. I believe Buck has some, and Pratt Burnerd as well. Could be others easily. The ones I remember seeing were all adjustable scroll chucks, like the Adjust-Tru style.

Buck recommends Forkardt PF on their instruction sheet:

http://www.buckchuckusa.com/userfiles/How to Mount and Operate(2).pdf

It's a good read, anyway. Lots of things there that would apply to any 3 jaw.