T&T: naiad knock

[Scott E. Bulger]

Bruce,

My boat had TRAC fins.  I got a small amount of movement and noise from the
Port fin as the "Trunion" bushing wore to a point of needing replacement.
The TRUNION busing is at the end of the Parker hydraulic cylinder that
actuates the fin for deflection.  There was just a tiny bit of play.  These
bushings are actually a maintenance item, designed to ware.  They are a soft
metal impregnated with oil or lubricant of some sort.  They actually ooze a
bit of liquid late in their life.  Anyway, I went through a pair after about
2000 hours of operation.  Another source of play in the system was a large
nut, much like an axle bearing nut that keeps the shaft centered in the
yoke.  On my stbd fin it didn't seem the factory did the preload just right
and it need a bit of adjustment.  My suggestion is find a really good Naiad
guy and have them take a look at it.  You don't want your stabalizers to
fail, oh, be aware if the potentiometer that measures fin position fails, it
can destroy your system.  That was the danger of some play in the shaft.
Fortunately I didn't have any issues other than adjustment and replacement
of the Trunion bushing.  Good luck!  Scott

Scott E. Bulger, Boatless in Seattle