Mandolin Banjo neck adjustment

[Kennyz55]

I want to lower the action on this mandolin banjo. Can i shim or how do you adjust it?

[pops1]

That is mostly to hold the neck to the rim. You can loosen the neck with string tension down and place a shim behind the end of the fingerboard, or preferably the neck below the fingerboard, then tighten up. You can also lower the bridge some. I also might ask what strings you are using. Mandolin strings, I feel, are too heavy for these. I use two sets of tenor banjo strings. If you think of the lows on a banjo with the light strings they use and that now you have 8 strings on a banjo head a .040 mandolin string is way too heavy. The banjo strings sound much better too. They may also help the action feel better.

[Tavy]

Assuming everything works the same as a regular banjo you should be able to lower the action by

1) Loosen the nut on the inside of the cross-rod at the tailpiece end, then,
2) tighten the nut on the outside of the cross-rod at the tailiece end.

If there's not enough adjustment doing that, then yes you will have to unbolt the neck and add a tiny shim to the top of the end of the neck. A 0.5mm shim is normally more than enough to make quite a difference to the action.

[Kennyz55]

I don't know what to loosen here on the inside. I can turn the outside. I assume clockwise is tightening????

[pops1]

That doesn't apply to your banjo, that only works with coordinator rod banjo's. Your banjo has a dowel stick. There are other ways more involved, but to just loosen and put a thin shim against the rim is the way to go if it gives you enough. The dowel can be steamed out and reset, but it is not an easy job. I have done shims at the opposite end of the dowel to move the angle, but again a little more complicated.