Removing a drill chuck arbor

[Doozer]

Only grease the screw. DO NOT grease the inside of the hood
or the outside of the jaws. If you grease it, it will NOT grab a
drill bit. It will be self tightening and self loosening!
Be very sparing with grease and no oil. Only grease
the screw and the balls.

-Doozer

[alanganes]

Alan, the schmoo in the chuck is way over the top. It sure does need a cleaning. But when you put it back together note that the friction cone surface inside the hood is by rights supposed to be dry. Same with the mating surfaces on the jaws.

No question! It was obvious as soon as I got the thing apart, the stuff was everywhere in there. It looked a lot like that cosmoline-like goop that they smear on tools to prevent rusting during shipping. It was semi-hardened and made the chuck very stiff in operation.

I cleaned it all out with some lacquer thinner and as Doozer suggested, put just enough grease to get a light coat in the screw threads and just enough on the bearing balls that they were sticky enough to stay on place for assembly. The thing opens and closes easily and smoothly now, much nicer than before.

I put in the new arbor, a straight 3/4" one so I can use this in my milling machine. I have not tried to check runout, but again this was a pretty inexpensive chuck so while you do get luck on occasion my expectations aren't that high.

I really appreciate all of the input.

[DR]

In years past and maybe still Jacobs instructions for removing arbors in cases like this was to cross drill the arbor, insert cross pin, then use wedges. Always worked for me. The arbor is still usable.

Something else, Jacobs arbors were usually soft. Low cost import arbors many times are heat treated. Not sure why.

On edit: here's a link to Jacobs recommended way to remove arbors. I don't get all this business about taking chucks apart.

http://www.jacobschuck.com/uploads/ueditor/file/20200604/1591240204146153.pdf

[jwmelvin]

Only grease the screw. ... Only grease
the screw and the balls.

Albrecht says "Take care not to put grease on the thread between spindle 2 and body 4. These surfaces have to be clean and dry in order to secure the function of the chuck." (Spindle 2 is the male screw; body 4 is the female thread). Other documents say "Caution – do not lubricate acme thread on body/spindle assembly."

e.g. here

[Doozer]

I have always kept the hood and jaws dry.
Putting grease on the screw never seemed
to make the chuck self loosen, but maybe
you are right to keep it dry too.

Q? Other than greasing the balls,
should you lubricate ANYTHING else?
The link you included does not mention
lubricating anything.

-D

[BCRider]

I mentioned earlier that I could not live with the idea of zero oil as in freshly degreased. So I applied a light coating then rubbed most of it off with a paper towel. On two chucks that were super lightly oiled where meant to be dry they are working fine. The other is still as it came from the box and works fine too. I can't detect any difference between the three of them. And they all work well enough that I can drive S&D drills with them.

[jwmelvin]

Q? Other than greasing the balls,
should you lubricate ANYTHING else?
The link you included does not mention
lubricating anything.

Yes, that link, to Royal's page on rebuilding and replacement parts, simply says not to lubricate the screw.

Albrecht's German site has a PDF with more, which states:
"-Put a lot of grease (water and heat resistant) on the balls, only a little grease on the guides. Take care not to put grease on the thread between spindle 2 and body 4. These surfaces have to be clean and dry in order to secure the function of the chuck. - Don’t grease the matching guides of shell 3 and jaw guide 1 so the air can escape during assembly."

I'm not purporting to know, I've just read not to grease the screw before (like in this popular guide), and figured it was worth mentioning.

[alanganes]

In years past and maybe still Jacobs instructions for removing arbors in cases like this was to cross drill the arbor, insert cross pin, then use wedges. Always worked for me. The arbor is still usable.

Something else, Jacobs arbors were usually soft. Low cost import arbors many times are heat treated. Not sure why.

On edit: here's a link to Jacobs recommended way to remove arbors. I don't get all this business about taking chucks apart.

http://www.jacobschuck.com/uploads/u...0204146153.pdf

In this particular case, there was virtually no shoulder on the arbor against which to use wedges like that. There was only a shallow radiused groove barely 0.050" deep. The tail of the arbor, being a Morse taper, got smaller from there. Beyond that I did not happen to have a pair of those wedges. Yes, clearly I could have made a pair. As it was, it honestly took less time to disassemble the chuck and push the arbor out than it took to read about how to do it. I was actually surprised how simple and easy it was.