Boat Winch maintenance

Winch overview

The winch can be disassembled very easily because all key components are bolted together. Whilst the winch usually continues to operate satisfactorily there are several points in the winch that harbour significant rust and left unchecked may cause the winch to seize or break.
The following section describes how to disassemble the winch, service and reassemble the unit.

Disassembly

Begin by unbolting the 10mm centre retaining bolt holding the main spool (need 15mm spanner). With the main spool removed the two main mounting bolts will be accessible. Remove the bolts (17mm spanners needed) and remove the winch casing from the bracket.

Unwind the strap and then undo the machine screw retaining the loop on the end of the strap (15mm spanners needed). The machine screw is highly likely to be very rusty as it is not galvanised and is usually subjected to extended periods of moisture soaked into the strap. The rust may have damaged the strap loop. Inspect the strap for damage, removing rust from the loop if needed. Ideally replace the strap retaining bolt with a stainless steel machine screw equivalent (10mm x 80mm) or clean and paint the existing bolt (galvanising spray is suitable). Clean and remove all rust from the strap hook. A rusty hook will abraid the boat painter. Add a little grease to the keeper spring and check that the spring and keeper work smoothly.
The spool centre bolt has a split steel bush (the bush has an open seam along its length). If possible remove both the bolt and its bush. Remove all traces of rust from the bolt and bush.
Clean the main winch case, taking care to remove any dirt and verdigris that may retain moisture.

Assembly

Start by bolting back the main winch case on to the bracket on the road trailer. Tighten securely.
The next stage is to replace the main spool. Grease the cogs on the crank mechanism. Grease the bush and insert the bush into the spool and insert the spool into the winch case, checking that the cogs on the spool and crank mechanism interlock smoothly. Note that the bush is marginally wider than the spool. Thoroughly grease the centre bolt and tighten securely. Test that the spool revolves freely.
Finally insert the strap loop into the spool and thread the retaining machine screw through slot in the side of the spool and the loop and bolt it securely. Wind the strap back on to the spool making sure that it lays flat and central.

TIP: The winch spends much of its time exposed to weather causing sun damage to the strap and worse perpetual rusting at the centre of the spool. After servicing and cleaning I cut a section of a plastic oil container to clip over the winch assembly and protect the winch and strap from rain. This has proved very successful in keeping the winch clean, dry and working smoothly.