Rebuilding an Albrecht Drill Chuck

Here’s another excellent article by Mikey.  It will show you how to take a worn or abused Albrecht keyless chuck and rebuild it to be like new. -  Rob

I was really stuck. No, this wasn’t the ordinary kind of stuck.  This was one of those seriously awful expletive deleted kinds!  Having just bought my first “genuine Albrecht chuck” on eBay, I was stoked.  I recall thinking, “I’ll just overhaul that puppy and have me a precision keyless chuck for cheap!” Talk about naïve – that first chuck brought me to my knees!

It resisted all my efforts to get it apart, had an arbor stuck in there that didn’t fit any of my machines, and I was beginning to have that sick “paperweight” feeling.  Yes, I did the penetrating oil and the hammer taps every time I passed it for three days, repaired my strap wrench twice, spoke a lot of “nice” words to it, lost sleep over it and almost picked up my torch!  Pathetic but all true.  Sound familiar?

I looked for help on the net and, to my dismay, found very little!  I won’t recap the misery that ensued but I did eventually get that chuck rebuilt and promised myself that if I ever learned to work on these things effectively that I would share it with my fellow hobbyists because nobody should have to go through that!  This is my attempt to fulfill that promise.

I have since rebuilt seven of these eBay specials and have learned a thing or two that work for me and I hope they work for you.  If you’re stuck like I was then read on and we’ll learn how to get the thing apart, get the arbor out, and get it back together again as painlessly as possible.

As always, work safely and proceed at your own risk.

We will use the C80-J2, a 5/16″ capacity chuck that I bought on eBay,
for our rebuild.  Its jaws were galled from a spinning drill bit in an
over-tightened chuck and were replaced during this rebuild.  The rest of
the chuck showed little discernible wear.

Albrecht Anatomy 101

The 5/16″, 3/8″ and ½” chucks in Albrecht’s Classic Series have the same anatomy, differing only in size.  Once you know how to work on one of them you will know how to work on all of these.  I have not worked on the other chucks in the series but suspect they are the same.

This is a cut-away of the typical Albrecht chuck and their nomenclature.

Typically, there are three obstacles you will face when disassembling an Albrecht chuck: getting the collar locking screw out, getting the hood off and getting the arbor out.  The rest is easy. I would encourage you to read this to the end before beginning work on your chuck as there are some CAUTIONS to be aware of.  When working on precision assemblies with parts that are expensive to replace please work carefully and take your time.

Disassembly

Before breaking down your chuck consider putting it in your drill press or lathe and use a steel brush to clean the knurled parts and gently polish up the smooth areas.  I suggest wiping it down with alcohol or lacquer thinner first to avoid burnishing in the surface contamination.  This is best done before you break it down so grit doesn’t get into your nice clean chuck.

• Remove the slotted collar locking screw.  Caution: Be sure to use a screwdriver that fully engages the slot to avoid damaging the head. Quite often these screws are in there really tight.  A 5/16″ chuck takes a metric size 4.5 screwdriver blade, while 3/8″ and ½” chucks both take a size 5.5.  I suggest you clamp the chuck in a padded vise so you can apply controlled pressure directly in line with the screw.  Once the screw is out wedge the tip of an old screwdriver into the slot in the collar to open it and the collar will simply slip off the tail of the body.

• Now we need to get the hood off.  Albrecht recommends clamping the shell in a fixture and removing the hood with a strap wrench.  Okay, maybe with their strap wrench!  My Klein strap wrench has only been able to budge the hood on one chuck but by all means try it.  If it fails …

  Here is an option that does not damage the hood and gets the tightest hood off in a few seconds.  Trust me – you want to make these.

• These two 3/8″ thick aluminum plates have holes bored to the diameter of the body and hood.  Once the slots are cut the hole opens just enough to fit nicely.  The small secondary hole is to prevent the plate from cracking under compression.  By the way, the factory uses this type of plate (1/4″ thick) to hold the shell when removing hoods.  Once made, label them so another chuck of the same size can be worked on.  You will need separate plates for different sizes of chucks, of course, but they are simple to make with a hole saw followed by a boring head.

• The smaller plate slips onto the body just below the angled step, while the larger one clamps onto the upper part of the knurled area of the hood.  The threaded part of the hood is at the lower part of this knurled area and no pressure is applied to it if you position the plate as shown.

  A large C-clamp is applied to the slotted side of the larger plate and the lower plate is clamped in a vise.  Tighten the C-clamp so it does not slip.  If the shell spins, tighten the vise (degreasing the plate and shell really helps here).  Use the screw of the C-clamp for leverage and even the tightest hood will come right off (RH thread).

  Once you have loosened the hood but before you take it off, move to your workbench and work over a shop towel or tray.

• Remove the hood and move the spindle up (turn the part of the body where the collar used to sit) about half way and slip the jaws out.  Now screw the spindle up further and it will push the jaw guide up so you can lift it off the shell.

• Remove the spindle and body by pulling them straight out.  Remove the 25 ball bearings. Caution: don’t drop them on the shop floor as you will need ALL of them.

• You should now be able to see the end of the arbor through the rear of the body, which can sometimes be driven out with a punch.  Caution: There is great potential for damaging the internal threads of the body here.  I would suggest slipping a small piece of thin-walled tubing in there before using a punch.  Also be very sure to fully support the end of the body where the arbor exits before you let the BFH fall.

• It isn’t unusual to find that the arbor is in there so tight that a punch fails to budge it.  Here is an option that has worked every time I needed it.

• Cut the arbor, leaving about ¼” of arbor sticking out.  Put the spindle body in your lathe and drill and tap for a bolt of your choice (I use a 5/16-24) at least ½” deep.  You want this bolt in the center of the arbor stub so tension is applied along the axis of the arbor.

• Transfer the body to a padded vise and find a socket/pipe/hollow thing that fits.  Using a heavy washer under the bolt head, tighten the bolt into the tail of the arbor stub through the socket.  The outer edge of the socket bears on the spindle body.  Most of the time this will pop the arbor out but if it doesn’t, use your punch from the inside and give it a few taps and the arbor should come out.

• If your arbor is through-hardened (most “hardened” arbors I have seen are case hardened) and you cannot drill and tap it then your best option is to use a hydraulic press.  Support the end of the body, not the ring halfway up, when doing this.

Your chuck is now completely disassembled and you can clean your parts with degreaser, then hot soapy water and blow them out.  After cleaning the spindle and body threads wipe them with lacquer thinner before setting them aside.  Now you can begin inspecting the parts to see if any are damaged enough to warrant replacement.

Smooth out any burrs with a diamond file.  By the way, Eze-Lap sells a little diamond-coated hook sharpener with a shank about 3/16″ OD and a coned tip that works well on burrs inside a chuck’s taper socket.

Now that the chuck is apart you can see how it works.  As the hood is tightened the spindle moves up.  The jaws, which are linked to the spindle, move up in the jaw guide.  Constrained by the inside of the hood the jaws close on the bit while the spindle pushes up on the bit from below.  The result is that the bit, once locked, effectively becomes a solid part of the chuck, thereby transferring the accuracy of the chuck to the bit.  As cutting forces are encountered the chuck actually tightens; the greater the force the tighter the chuck becomes.  Neat design, huh?

The above scenario is only true as long as the spindle and body are clean and dry.  If oil gets into the spindle assembly it cannot resist the cutting forces and the drill will slip – this is the Achille’s Heel of keyless chucks of this design and the fault of the user.  Attempts to over-tighten the chuck will not work for long and the drill can slip badly enough to gall even the hardened jaws of an Albrecht chuck.  This is why so many chucks sold on eBay have severely tightened hoods, really tight collar-locking screws, vise marks on the collars and worn jaws – oil in the spindle!  The point I want to make is that if a drill ever spins in your Albrecht chuck, please take the time to disassemble it and clean the spindle assembly.

As for the stuck arbors, well, don’t get me started …

Assembly

Guy Lautard wrote a treatise on this subject in one of his excellent Bedside Readers.  There were several (paraphrased) notes there that are important:

• Inspect the inside of the hood.  The jaws ride on this surface and there needs to be some “tooth” to it so take some 320 grit sandpaper and scuff the inside of the hood where the jaws ride – they will look shiny and you’re trying to remove the shine.

• The spindle and body must be clean and dry. :-)

Except for the area holding the bearings a very light application of lubricant is all that is necessary.  Assembly is essentially just the reverse of the above.

• Apply grease to the bearing seat.  I also use a light coat of grease to the area leading out the back of the shell, toward the arbor taper, to prevent any grit from working into the bearing area.

• Insert all 25 ball bearings.  I use an acid brush to apply grease during assembly and stabbing down onto a bearing traps it at the tip of the brush, allowing you to transfer it to the bearing seat area.  A broad-tipped tweezers is faster but avoid squeezing too hard or you’ll launch the bearing.  Remember the shop towel!

• Once all the bearings are in place you can apply light grease to the underside of the body where it contacts the bearings (don’t get grease on the front side) and slide it into place.

• Apply some oil to a Q-tip and lightly oil the jaw guide slots where the jaws will ride.  I also lightly oil the inside of the hood at the jaw contact points.

• Insert the clean dry spindle (LH thread) into the clean dry body.  Caution: Okay, I’ll spare you further comments about oil but you get the point.

• Slide on the jaw guide, being sure to line up the drive pin.  If your drive pin is somehow damaged you can replace it with a standard roll pin cut to size.  Now spin the spindle up about halfway and insert the jaws.  (Contrary to what I have read on the net, the jaws are not matched to their carrier so numbering or otherwise marking their original position is not necessary.  If they were matched what would you do with replacement jaws?)

• Lightly oil the threads on the shell and screw the hood in place.  Put the chuck back in your fixture and tighten the hood with a strap wrench.  Do not apply excessive pressure here – just snug it. It gets tighter in use.

• Wedge a screwdriver into the slot of the collar to open it up. Slide the collar up against the bottom of the shell, leaving just a tiny bit of clearance so the hood moves freely.  Lightly oil the collar locking screw and just snug it down – you do not need excessive pressure on this screw.

Conclusion

Congratulations, you’re done!  Your chuck should now feel smooth and precise and is ready to go to work in your shop.  No ongoing maintenance is usually required in the hobby machine shop setting.  An occasional light coat of oil externally will keep any rust at bay – try Camelia Oil for this … you’ll love it.

Our rebuilt chuck drilled a 1/16″ (0.0625″)
hole in the end of a 0-1 steel rod held in an
ER32 collet on my lathe; it went straight in
with no wandering at the tip.

Mikey, 2008