Preparing your boat at the beginning of the season (6/7) : Winch maintenance

Nicolas Venance - Boat Technical Journal

On a modern sailboat, the high leverage of winches allows us to sail with a reduced crew while benefiting from the strength of half a dozen strong men! But how do you maintain a winch to avoid unpleasant surprises?

For example, a 40 mm winch (average size for a mainsail) will furl a force of almost a ton. To get the best out of them, winches need to operate with the minimum of unnecessary friction. A dirty winch, full of salt and old grease, generates internal friction which can cause it to lose a significant part of its efficiency.

Today, we focus on the annual maintenance of these little jewels as practiced in charter.

A winch is composed of a baseplate which remains fixed to the boat, on which a box body and its mechanisms (bearings, pawls) are inserted, the whole topped by a headstock and surmounted, for the models having it, by a self tailing (device allowing to retain the halyard or the sheet embarked on the winch.

It contains small pawls and springs that can easily jump into the water.

Tips : To avoid being dismayed when a winch pawl spring swims into the harbor, prepare a large (40cm) basin beforehand, which you will drill with a central hole 3 to 4 cm smaller than the headstock.

This bowl will hold the small jumping pieces.

Important Disassemble only one winch at a time to avoid confusing the parts, or take the parts of each winch with you in a bucket marked with the winch's location if you're going ashore for cleaning.

To dismantle and maintain your winches, you need

An exploded view of your winch (available on the manufacturers' websites)
A complete set of Allen or Torx wrenches depending on the brand
A flat screwdriver
A tube of waterproof silicone grease or winch grease
A can of fine oil
A degreasing agent such as gasoline "F" or diesel
A bucket
A jar for the degreaser
Two brushes (one for the degreaser the other for the grease)
Another basin
Rags
Waterproof mechanic's gloves

Dismantling

Let's start the disassembly step by step following this sequence (put all the disassembled parts in the bucket); NB, the sequence of operations may vary slightly depending on the manufacturer:

Start by removing the screw at the bottom of the crank tube, using a flathead screwdriver or Allen key as appropriate.
Remove crank tube. image extract shaft
Lift the headstock slightly to remove the self-tailing finger.

Carefully remove the headstock (paying attention to the presence of any glued bearings which may come with the headstock when disassembled). Place the headstock in the bucket.
Install your anti-fall perforated basin!
Remove bearings, place in bucket. image remove bearings
Unscrew the five or six screws from the winch body and place them in the bucket.

Carefully remove the winch body. Be careful, this is when the "jumping" pawls may start to fall into the water. Inspect pawls and springs.

Remove the winch gears and store them in the bucket.

Degreasing

As with any gearbox, the system in the winch body is designed to operate with the minimum of internal friction.

The mixture of salt and grease or oil produces a kind of paste which increases the adherence and therefore the friction between the moving parts. The degreasing operation consists in removing all traces of impurities present in the mechanism.

To do this, fill your jar one-third full of diesel or "F" gasoline and, with a brush dedicated to this purpose, degrease the parts one after the other. Place the jar in the basin, along with the clean parts. Gradually remove the dirty parts from the bucket for cleaning.

Lubrication

A simple thing to remember: Grease the sprockets (toothed parts) and the axes and oil the springs, bearings and pawls.

To grease, place a dab of grease on your second brush and spread it evenly over the parts, without excess.

Reassembly

Proceed in reverse order. Once the gearbox body has been reassembled, oil the bearings lightly, then grease the headstock teeth. Grease the crank tube and complete reassembly.

Wipe off any excess oil or grease with a cloth.

These few simple operations will ensure that your winch delivers its full power in all circumstances. Carried out once a year, they will ensure the longevity of your equipment and the comfort of its use.