It really depends on the furler design. Some bearings, like the torlon or delrin ones used in some furling units are designed to be greaseless and spraying them with WD40 may actually interfere with their performance, as WD40 will still tend to collect some dirt. Others, which have steel bearings, are required to be greased regularly, and spraying WD40 will remove most, if not all, of the remaining grease.
You are right again SD. But I offered the advise I did because I am intimately familiar with this system.
Originally Posted by wumhenry
According to the service manager at the boatyard where I keep my boat, which is equipped with a 1980s-vintage Hood furler, the steel bearings should be replaced every four years.
With all due respect to the service manager, the bearings don't need to be replaced until they begin to give you problems.
Some of the 1980 Hoods used sealed bearings. Not stainless. These bearings should be repacked annually but usually aren't. If the bearings aren't full of grease, water will work it's way inside and if allowed to sit for a few weeks the bearing will freeze up.
Just last week I serviced one of these and the bearing was frozen solid. The owner had been using it that way for years. The entire frozen bearing was spinning.
Fortunately, he didn't do a lot of sailing.
I was able to remove the bearing and free it up.
It's working now as well as it did when it was new.
The bearings in a roller furling system are not like bearings in a high speed, high load piece of machinery. You can restore a frozen bearing and it will work fine.