Lewmar markets an expensive grease. The
marine stores also sell expensive stuff.
I use a low viscosity EP
wheel bearing grease. Winches are so over-built relative tothe loads most of us apply - especially the older ones. I rebuilt all 17 on our
boat when we bought it. They had not been well serviced in 30 years. Lewmars from 30 to 65. All old dry grease and lots of dirt. I removed them and disassembled each into a 5-gallon pale. Took lots of photos of the big ones so there would be no re-assembly
mistakes. Each pile of
parts spent a day in the soak tank in the shop where I
work. You can have this done at an auto machine shop or just use mineral spirits. Use a tooth brush, rubber gloves, and dry the clean
parts with rags. Do not over-grease as this will make the action sluggish. Especially go light on the pawls. Each
winch left about 2 tablespoons of insoluble hard particles. I found an on line site for a few replacement parts such as pawls & springs. Some parts were obsolete & unavailable so I made
replacements in the shop. Its nice to have a machine shop.

Afterwards, We re-bedded all. Many
cabin top
leaks were fixed.