After reaming the endpin hole, vacuum out any sawdust and debris from inside the guitar. It’s always good to keep the guitar’s interior clean.

Installing the endpin jack. Before you install an endpin jack like this one, be sure to test the hole to be sure the jack fits correctly. The jack should be snug, but not so tight that you have to force it into the hole. If the hole feels too small, ream it out a bit more. Be patient and go slowly—never be in a hurry when drilling holes into a guitar!

Fig. 4. Install the rear nut and lock washer before mounting the jack from inside the body.

The next step is to install the rear nut and lock washer (Fig. 4) before mounting the jack into the hole from inside the body. To help with this tricky operation, insert a Phillip’s head screwdriver through the hole from the outside to help guide the jack into place. Slide the jack along the screwdriver shank until you can grab the jack from the outside and pull it into place.

Fig. 5. (left) After adding the external washer and nut, check the available threads as the jack protrudes out of the endpin hole. Will they accommodate the screw-on strap-button collar? Fig. 6. (right) The strap-button collar should be flush
with the end of the jack.

Once it’s in place, check how much of the jack protrudes from the hole. Add the external washer and nut (Fig. 5), and then make sure there are enough accessible threads to grip the screw-on strap-button collar. It should be flush with the end of the jack (Fig. 6).

With the external washer, nut, and strap-button collar installed, the jack should be tight and not wiggle. If the jack is still loose, reach inside the guitar, remove the jack, and add a few turns to the interior nut and lock washer. Once the jack lines up correctly and is flush to the strap-button collar, remove the collar and tighten the outer nut. Finally, reinstall the collar.

I don’t recommend adding any glue or adhesive to the threads. This can cause a lot of damage and aggravation if you need to replace the endpin jack. This type of jack is designed to be tightened and loosened from the outside of the guitar. Adding adhesive interferes with the process and can cause problems down the road.

Fig. 7. The endpin jack comes prewired to a harness that plugs into the M1-Active.