If you are like most sailboat owners, you haven't serviced your winches since you bought your boat. You need to grease your winches because they are probably one of the more expensive items on your boat.
Winches can be a little intimidating. They are not as bad as they look — even though when you first pull off the drum it looks like the gears and bearings are laughing at you.
Every winch is different from the next, so there is no good way to try to memorize how a winch goes back together. However, the one thing that works to your advantage is that a winch cannot be put together wrong because the parts will only fit one way — with the exception of maybe getting a washer in the wrong place. If you do find yourself in trouble, Harken has assembly diagrams and you can actually download a parts breakdown at www.harken.com. After you've done one, you will realize it is not as hard as it seems.
It is a good idea to have everything handy before you start because you will be too greasy to dig around your clean boat for needed items. The things you will need are: lots of paper towels, mineral spirits, coffee can, small paint brush, winch grease, and tools including metric Allen wrenches, and hot water access.
The mineral spirits will be poured into the coffee can and used to clean parts with the small paintbrush (after cleaning, rinse all the parts in hot water). The first step is to remove the drum from the base of the winch.
This step will vary from manufacturer to manufacturer. Harken uses a screw at the bottom of the winch handle socket. Simply unscrew it, pull the socket out, and lift the drum off. The basic idea is that the line-peeling arm keeps the drum in place. Other winches simply use a split ring to hold the drum down. Removing the split ring can get a little tedious, but you can usually get it off by hooking a corner of it with a knife. As you lift the drum off, be aware that the roller bearing cages like to momentarily stick inside the drum. The roller bearing cages then drop out unexpectedly. Just make sure they don't bounce off the deck into the water!
Now you are at the point where you will have to remove all the gears and bearings for cleaning. Even though (as I said before), the winch only goes back together one way, it wouldn't hurt to take a real good look at everything. More importantly, take note where the washers and other little items go, because it can be hard to figure out their location. Don't waste too much time worrying about the larger gears and drive shaft because it will be easy to find their homes. Pulling the gears and bearings out is actually quite simple and doesn't require any tools or skill. They just slip over the gear shaft, so all that needs to be done is to lift them off the shaft by hand.
Now take the gears and bearings, and anything else that looks messy, and place them in the coffee can. Fill the can with just enough mineral spirits to cover the parts, and let them soak for a while. Some filthy parts may need to soak over night.
After soaking, take the small brush and work the old grease off the part. When you are cleaning the parts, don't forget to clean the gear ring on the inside of the drum. After all of the old grease and grime has been removed, it is important to rinse the parts in hot water. The hot water will remove all of the mineral spirits, which if left on, would break down your new grease.
Now, take a deep breath because it is time to reassemble the winch. As you are putting all the gears back into place, you will want to take a close look at how the pawls are operating. Pawls are the things that go "click, click, click" while the winch is being turned, and they are the heart and soul of the whole thing. If they don't open and close smoothly and lively, the drum could actually spin backward - ruining the whole sailing trip. So, if there is any question that the pawls are not working properly, it is much easier to just replace them and the little springs. Also, it is very important NOT to grease the pawls because the grease will cause them to stick, and if they stick, the gears won't engage. Instead, lubricate them with any light oil that might be on hand.
The final step is to place all the winch parts back into the base where they belong. If you end up with extra parts, instead of tossing them in the water when nobody is looking, you will have to go back through each part and play detective until its home is discovered. Also, it's not a bad idea to periodically give the shaft and gears a spin to make sure you are on the right path. Once you are certain the winch is reassembled correctly, lightly brush on some clean winch grease. Don't think by packing them with too much grease they will last for years and therefore they won't have to be serviced for a while! This only makes a big mess down the road. Now that the gears and bearings are all in place with new grease, all that needs to be done is to remount the drum. That's it!
You're done…at least with one winch!