Seal...what seal?
All there should be is a clear flexable plastic tube with the opening near the winch drum. If your cable is in good shape without any broken strands, you could pack some plastic brillo pad material into the tube to keep the water from splashing up and out of the tube. The cable will still slide through the brillo material without problem. Worked for me. If there is a leak around the pipe that the clear plastic tube is connected to, try fiberglassing that area. Oh....I just realized that you may be talking about the keel pivot bolt. Easy fix: With the boat on the trailer and still connected to the tow vehicle, and using wood blocks to position a hydraulic bottle jack, position the bottle jack approximately one foot to the rear of the area of the pivot bolt. With a helper carefully lowering the swing keel to engage the hydraulic jack, be prepared to push the bolt out of the keel trunk as the weight is relieved off the bolt. The bolt used to push the original keel bolt out functions to maintain the alignment of the keel to the hole. When you are ready to install the new bolt and rubber washers, push that temporary bolt out with the new bolt. That's basically how it's done. Caution: if you don't keep the trailer connected to the tow vehicle, there will be instability with weight change as you and your helper move about the boat.
