This fiberglass rudder retaining ring shim supports the weight of the rudder. It lives above the fiberglass "tray" at the bottom which ultimately is what takes the load. The tube is laminated over a mandril for an accurate size. A laminate of fiberglass and vinyl ester resin is used for strength. You must trim the length to fit your boat.
Dimensions:• Length: 2.875"
• Inside diameter: 2.86"
• Outside diameter (approximate): 3.38"
• Catalina 310
• Catalina 320
• Catalina 34 1989, hull #1027 and later
• Catalina 36 1989, hull #1040 and later
A combination of rudder bearing components and this rudder retaining ring have been observed aboard:
• Catalina 380
• Catalina 400
1) Some customers report that their early boats used an aluminum ring instead of this fiberglass ring. The aluminum can become badly damaged due to galvanic corrosion since it is installed on the stainless steel rudder post. This can cause the aluminum tube to collapse allowing the rudder to drop. Replacing the aluminum ring with this fiberglass ring solves the problem.
2) Other owners report that the pan below the retaining ring has subsided either because it has failed just below the retaining ring or because the bond that secures the pan at its perimeter (on some models) has failed. If either is the case, a new retaining ring will not solve the problem. However, of your boat has the aluminum ring, it should be replaced while repairing the other damage.