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old Jacobs 16N?

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  • old Jacobs 16N?

    I picked up an older Jacobs 16N ball bearing chuck. It is cosmetically good. Looked great in a picture. When it got here, though, I spun the sleeve to open it a little and uh oh, it was nearly frozen. I worked some oil in and worked it in and out by hand several times. It is quite a bit freer but it is still not right at all.

    I rebuilt a Jacobs 3A once. But I've never been into one of their "super chucks". Anyone got any wisdom? Ideas to try?


  • #2
    They come apart easily and the bearing doesn’t get in the way. It’s large so disassembly forces are high. Should be plenty of YouTube videos out there.


    • #3
      You didn't say whether the 16N chuck was USA made or the newer serial numbered chucks.

      I've refurbished a few Ball Bearing Super Chucks, retract jaws, press off the sleeve. Make sure you note the placement of the jaws
      the jaws have a notch code, they're not that apparent. Clean, grease and reassemble, it can take a bit of fiddling to sync the jaws back, press on the sleeve.

      Stay away from the new replacement bearings that Jacobs is selling currently, aside from being really expensive, they've redesigned the bearings,
      they're no longer loose balls riding in a race it's a plastic caged bearing, the new jaws seem to work fine in older chucks.
      Hunt on ebay for the older rebuild kits, a lot less money.
      Added pictures of the new thrust washer style ball bearing and the intructions for the notch code, I disregarde the pressing on the jaws
      and retract them so I'm pressing on the nose of the chuck.
      Attached Files


      • #4
        I've done a bunch of the Jacobs ball bearing chucks, they're really simple to work on. If possible I like to have the jaw tips at least level with the end of the chuck or further out, that's so that there's no risk of the other end of the jaws catching on the sleeve. I always press on the end of the chuck, never the jaws.

        The bearings are a standard size from what I remember, I think I bought a bag of replacements for not much money for one of them as the races were fine but the bearings were pitted. Based on my experience you'll probably find it full of dried crusty grease and nasty gunk. Once that's all cleaned off and grease has been liberally reapplied it should, fingers crossed, work perfectly