Renovating Vintage Jacobs 633C Drill Chuck: Craftsman King-Seeley 103.23141 Drill Press Restoration, Pt. 18

Almost all the bits of the press are finally ready to be reassembled. However, when I went through cleaning and polishing parts as described in the last post, I discovered I still needed to service the chuck.

You may recall my post about removing the chuck a while back.  Now it's time to disassemble it, clean it up, and put it back together.

The chuck is a Jacobs 633C 1/2 inch model.  These types of chucks were standard on many thousands of presses over the years, and Jacobs is still the most common chuck found on modern hand drills and drill presses.

Sturdy, well designed, and easily serviced.

I'm following Jacobs' instructions, which haven't changed for decades.

I sprayed some PB Blaster penetrating oil into the area between the body and the sleeve of the chuck. This helped in separating the parts.

With the jaws out of the chuck about halfway, we put the chuck in an arbor press to press the sleeve off.

You'll notice I put two pieces of hardwood (sycamore I believe) under the edges of the sleeve, since my press is small and the sleeve won't fit on the base of the press.

What will happen here is that we'll press down on the jaws and the sleeve will slide off...hopefully.

Turns out the wood wasn't hard enough to withstand the downward pressure - it dented and then split.

So I used the scraps of pipe that I made the removal tool from (see that link above which describes the homebrew tool).

They worked perfectly.

You can see the base of my press - if yours is larger, you might not need to support the sleeve as I did.

The sleeve wouldn't budge when I worked the press by hand. So I whacked the press's handle and voila! the sleeve came off.

You can see the old dried up lube on the body of the press. We'll clean that up and put new synthetic lube on.

Next we remove the nut that engages the jaw threads and makes the jaws go in or out...or is it up and down?

The nut is in two pieces - it's formed as one piece then broken in two to fit exactly on the body around the jaws. If you work on one of these, you'll note how precisely the halves go together.

My chuck probably hasn't ever been opened up since it left Jacobs in 1952 or 1953, so I needed a small screwdriver to open the halves.

Note that the nut threads taper downward to fit the jaws - the wide end goes down when putting it back together. There's also a ridge on the nut at the same place as an identifier.

The jaws will now slide down out of the body. Note that the jaw numbers are embossed on the body on this specific chuck. I don't believe they all are, but his one is. (That is the "2" I'm referring to).

There are 3 jaws and they need to be assembled in specific locations in order that the jaws will open and close together exactly. So it's a good idea to note which jaw is which when you take them out.

(You may still make a mistake, but at least you tried to keep them straight.)

The jaws just slide down out of the body.

There are fine tines on each jaw. These are what hold a drill bit in place. Examine them, looking for chips, cracks, or other issues. Mine are in perfect shape as you can see here.

If the tines are worn or chipped, they won't properly hold a drill bit. Jacobs does sell kits to replace the jaws if yours are shot.

Fortunately, the only problem with mine is all the decades-old sawdust packed around them!

You can also see how I numbered the jaws to identify them.

With the chuck disassembled, I cleaned and polished all the parts.

I soaked everything in denatured alcohol to clean the parts. There was some light corrosion on the body and sleeve, so I used a rust remover to get the corrosion off.  Then I polished the sleeve, the nut, the outside of the jaws, and the attachment sleeve with aluminum polish.

Looks good, huh?

Reassembly is straightforward.

I put a light coat of synthetic lube on the curved part of the jaws where they fit into the body. And I also put a thin coat on the threads as well.

Turn the jaws sideways a bit and they slide right into the body.

I wiped the numbers off before I reassembled them, if you're wondering.

Slide the jaws all way into the body.

They should now align and the nut halves should line right up.

I found that holding the body with one of the nuts on let me see the threads and make sure they lined up.

At this point, you can test the jaws' opening and closing by holding the nut and turning the body.

After I had both nuts on and tested the chuck, I discovered the jaws didn't line up equally when the jaws were all the way out. Naturally.

Somewhere I mixed up two of the jaws. This is not a disaster. Fortunately. Jacobs has a diagram on that page I linked to above that identifies each jaw number by the pattern of its teeth. I easily found my mistake and put the jaws in correctly. So much for trying to keep them straight!

Here we have both halves of the nut in place. If you look closely, you'll see this picture was taken with the jaws in the wrong locations - one protrudes more than the other two.

After straightening out the jaws issue, I can press the sleeve back on.

You could do this with an arbor, but decided to just tap it on in a vise with a wood block and a hammer.  The jaws are facing down here, and I'm hitting on the threaded mount.

Here's our newly serviced Jacobs 633C chuck, ready for many more decades of service.

It works great - super smooth and fast to adjust. Very nice to use.

You can see the jaws meet perfectly. Look at how precise the whole thing is - the jaws fit exactly into the opening. What a beautifully made device.

And this is a shot of the embossed model number.

The complete restoration saga

Part 1 - Beginning

Part 2 - Electrolysis to Remove Rust

Part 3 - Grinding to Remove Rust

Part 4 - Leveling Base Table

Part 5 - Recreating Model Number Label

Part 6 - Refinishing Base

Part 7 - Removing Motor

Part 8 - Motor Disassembly

Part 9 - Motor Bearing Replacement

Part 10 - Start Capacitor and Motor Reassembly

Part 11 - Removing Threaded Jacobs Chuck

Part 12 - Spindle Removal

Part 13 - Quill Disassembly

Part 14 - New Quill and Spindle Bearings

Part 15 - Engine Turned Aluminum Trim Proof of Concept

Part 16 - Engine Turned Aluminum Trim

Part 17 - Cleaning and Polishing Hardware

Part 18 - Jacobs 633C Drill Chuck Restoration

Part 19 - Cleaning and Polishing Column

Part 20 - Reassembly Begins

Part 21 - Restoration Completed