How to remove this arbor?

[Aram]

I bought this very nice, used Jacobs chuck. It has more runout than I like, though. My old chuck ran so true I could barely measure the runout, so it has to be something in this chuck/arbor. I want to replace the arbor and see if that helps.

The chuck doesn't have a hole in the bottom, so I can't punch it straight out. The arbor doesn't have much of a shoulder, so I'm not even sure that wedges will work. It does have a couple of cross holes. I tried a couple of dumb things one of them, but no go. Any suggestions? How can I separate the arbor from the chuck?

Thanks.

[MstrCarpenter]

Did you try to just unscrew it. Should be a normal right hand thread. (Turn chuck or arbor counterclockwise to loosen.)

[handi]

I bought this very nice, used Jacobs chuck. It has more runout than I like, though. My old chuck ran so true I could barely measure the runout, so it has to be something in this chuck/arbor. I want to replace the arbor and see if that helps.

The chuck doesn't have a hole in the bottom, so I can't punch it straight out. The arbor doesn't have much of a shoulder, so I'm not even sure that wedges will work. It does have a couple of cross holes. I tried a couple of dumb things one of them, but no go. Any suggestions? How can I separate the arbor from the chuck?

Thanks.

The presence of a hole at the base of the arbor indicates it may be a threaded one. 

In either case, twisting may be the answer. Use the holes to get a grip.

[oakey]

last one of those i removed from the chuck i welded a plate with a hole that fit over the taper .
leave a space for the wedge
they make wedges just for this but any type of wedge should work
just one good solid tack weld let it cool completely drive the wedge that is used to remove it from the quill between the body and the plate .
A large nut welded on would be just as good does not take much of a weld as the heat does its part to
i have seen chucks that were just driven of in a vice pretty much ruins them i think its common to find them with no hole to allow a punch
that one might allow you to place a washer and a spacer or stack of washers then place a good hard pin through the hole in the end use the wedge between the washers and the chuck
edit
i have never seen one threaded on but handi just might be correct no harm in just chucking the flat end in a vice and see if it is threaded on turn it the right way opposite the rotation in the drill

[Timberwolf]

last one of those i removed  from the chuck i welded a plate with a hole that fit over the taper .
leave a space for the wedge
they make wedges just for this but any type of wedge should work
just one good solid tack weld let it cool completely drive the wedge that is used to remove it from the quill between the body and the plate .
A large nut welded on would be just as good does not take much of a weld as the heat does its part to
i have seen chucks that were just driven of in a vice pretty much ruins them i think its common to find them with no hole to allow a punch
that one might allow you to place a washer and a spacer  or stack of washers  then place a good hard pin through the hole in the end use the wedge between the washers and the chuck
edit
i have never seen one threaded on but handi just might be correct no harm in just chucking the flat end in a vice and see if it is threaded on turn it the right way opposite the rotation in the drill

.......................
It's probably a Jacobs #33 taper on a #2 Morse arbor.....check this out.............

http://www.jacobschuck.com/drill-chuck-removal-guide

[Aram]

.......................
It's probably a Jacobs #33 taper on a #2 Morse arbor.....check this out.............

http://www.jacobschuck.com/drill-chuck-removal-guide

Thanks. I think it is Jacobs #3 taper. (But if it twists off, I guess I'll find that out soon enough.) Great link, much appreciated.

[bjmh4]

I've drilled many of these chucks--most any of the key type can be drilled for ejecting the arbor in a press. (Don't ever try it with a keyless) Another method is to drill and tap the tanged end of the arbor and use a short length of tube or pipe and a heavy washer and bolt to "pull" the arbor.  I suspect the cross hole was drilled to insert a pin in an attempt to use wedges to remove the arbor. Doubt that it's a threaded arbor.

Bob

[EvilTwin]

If it says J33 or jt33 somewhere on the chuck then its a J33 taper. Probably really tight on it. I'd be more inclined to suspect the chuck itself then the mt2 spindle its mounted on. But good luck either way.

[jp4]

I just changed the arbor on a jacobs 18 chuck with a 4JT.  There was a screwed in plug on the bottom of the chuck.  When removed you could see the arbor.  I placed a pin in the hole to press on the arbor.  I placed a bearing splitter on the bottom of the chuck body.  Not having a press, I used a gear puller.  I put it under load and a couple whacks on the gear puller and it popped out.

[blackhat]

Before you beat the snot out of it, have you washed all the old crud out it and checked for burrs or flaws on the chuck jaws?  Do the jaws move evenly and smoothly?