It's very important to grease the keel screw every 2nd year.
It looks difficult but it's really easy. The screw is a naval bronze jackscrew
and very strong, but the shape of the keel lends itself to damage if sailed
into a rocky shoal at high speed. As a precaution after launching, always
lower the keel in shallow water at the dock in case it decides to fall off the
boat and go to the bottom.
On dry land, (as on a trailer) block up the centreboard in the fully retracted
position from under the hull. Remove all the stainless screws holding the
fiberglass cover onto the centreboard trunk top. Inside there are 4 large pop
rivets holding the metal screw plate retainer down. Drill these out. Using the
square wrench provided for the purpose, turn the square nut counterclockwise,
raising it and the screw out of the lead keel assembly. Raise it as far as
possible and grease the jackscrew with waterproof yacht winch grease (get this
in the sailboat chandlery). Grease the nut at the bottom, and screw it all
home again. Take this opportunity to check and if needed replace the ball
bearing race. The bearing race is readily available from C&L Boatshop.
If the screw seems to bind too much when first raising it, either the grease
is really dry, (Squirt oil down the shaft) or the screw has been bent from
running the boat aground. (hopefully NOT!)