Wednesday, February 5, 2014

The Sultry Winch

Winches on board sailboats make trimming sails much easier - unless they're frozen.  Such was the case here. Desiree's bronze,  Lewmar 40, two-speed Mothers of Mechanical Advantage brought low by the elements.

These winches adorned their delaminated pads as leaves composted in the main spindle, old grease congealed on the gears and bees (yes bees) made their homes under the casing in between the cogs. That said, these are made super-tough and of good material so they can take a fair amount of abuse. Getting them back in order, however, took a lot of elbow grease, WD-40, a couple of new pawl springs and winch grease.

Once you remove the locking ring from the main spindle, the whole casing will lift right off. These rings can be tricky, but a screwdriver or knife edge will let you get the purchase you need. Once the ring is off and before lifting the casing, take off the metal plate around the spindle. Beneath it you will see two pawls designed to keep the winch operating in one direction. These pawls have little springs in the middle. Take the pawls out with care so as to not lose the spring (the first time you do this - and probably the second - you will likely lose the spring anyway; don't say I didn't warn you, but have some spares handy).
The Naked Winch

With the casing off, the roller bearings lift right off.  I find that a toothbrush and WD-40 will clean these about as well as anything, but it is a messy job and you will go through a lot of rags or paper towels.

The Lower Gears 

The lower gears are held in by a spindle (it's the shiny metal square on top of the lower gears in the picture above).  This spindle goes through the middle of the gears and they turn around it. In winches such as Desiree's  that have sat for so long, old grease has caked up around the spindle which either inhibits the gears' ability to turn or it stops them completely. In my case, the spindle was frozen - mostly because of gunk rather than from rust or corrosion.

Before you can remove the spindle, it has to be rotated such that it will come out clean. In it's working mode the flat square metal tab at the top of the spindle rests under a lip on the housing. This prevents it from coming out unexpectedly.

In the picture to the left, this tab is under the housing. In the "Naked Winch" picture above, it is rotated ready for removal. In my case, getting this tab to rotate took a lot of Liquid Wrench and some gentle, strategic taps with a hammer via an awl.

To remove the spindle, it may be necessary to invert the winch and tap with an awl or a small wooden dowel and hammer from the bottom. This does not require a lot of force - just enough to kick loose the junk and push the spindle up through the gears and housing.

Here you can see the spindle almost free of the gears. Remove the spindle and the gears and clean them up. Again, a toothbrush and WD-40 does a pretty fair job; look carefully though, some of the old grease will have hardened on the cogs or spindle and may need to be scraped off. A knife edge will usually do the trick. 

Here are the dirty pawls, spindle, pawl springs and a bunch of gunk. 

Lubing the Winch

I have heard and read about people using all types of different greases on the winches to good effect, but I simply used a tube of West Marine winch grease because it is what I had. White lithium grease also works well and some have suggested Water Wheel Bearing grease. In any event, you want something that will stand up to the marine environment. Once you lube the lower gears and the roller bearings, you're pretty much good to go. Reassemble taking particular care not to lose the pawl springs. They can be a little tricky to get in, but not impossible. It's a good idea to have some spares even so.  NOTE: Do not grease the pawls. You do not want them to get gummed up. A couple of drops of 3:1 machine oil will do you there. 

My experience with winches are that they are generally bullet-proof. In consequence, they are often neglected.  In truth, they should be dismantled, checked, cleaned and re-greased at the end of each season or as part of the fitting out work in the spring. It doesn't take long to do and you'll notice the difference. Winches carry heavy loads and their failure under load can be, if not catastrophic, at least exciting - but not in a good way. 

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