The DS I centerboard handle is cast in bronze, sometimes crome plated, and will break if too much pressure is applied, but I doubt if you would break something on the inside. The centerboard handle has a one inch square section that fits into a square bronze plate thats molded into the centerboard head. The centerboard trunk has a larger circle machined into it that the centerboard handle turns within.
If your centerboard leaks a little, try putting vaseline around the gasket. Remove the centerboard handle to get to the gasket. If you need a new gasket call Allen T. Jones at 541-241-2575 he has a supply that is adveritised in the Day Sailer Quarterly, the Day Sailer Association publication.
You may have some sand, gravel or mud in your centerboard trunk. Roll your Day Sailer on its side on the beach. To do this you will need two and maybe three people, two get in the water and lift near the chain plates, the other person pulls on the side stay and when its over far enough pulls the mast down to the ground and sits on the mast while you work on the centerboard. Use the handle or cable to pull the centerboard out. Inspect the centerboard and trunk. Look for scratches, cracks or splits on the centerboard. You may want to remove the centerboard and sand the centerboard head, how ever, I have seldom found this to be the case. Most of the time the centerboard head it to loose and knocks around when sailing in chop. Loose centerboard head will allow stuff to get jamed in there. Let me know if you have a particular problem, I may be able to help.
Gus Heismann (marktdes-at-oneimage.com)