A Martin in for a loose endpin jack that needed the internal nut adjusted to properly allow the external nut to be tightened. The internal nut on the jack is the key to getting a nice tight fit in the tail block and still allow the instrument cable to properly seat in the jack. If the internal nut is too close to the outside of the jack, the external nut will not allow your cable's plug to get "all up in there."
![2014 Martin Custom X-Series X1-000E [4.6 lbs] :: loose jack](https://images.squarespace-cdn.com/content/v1/53dfcee2e4b0c0da377c65c7/1459893556559-40OSHIATNF3MWHMFYUIW/20160405_2014_+Martin_Custom_X_body.jpg)