Yes, you're right about oil, not grease, being used - as I noted, Bonfiglioli fills these at the factory with Shell Tivela S320 weight gear oil, not grease, and considers it permanent lubrication, expecting 25,000 hours of operation. Unfortunately, as many of us have experienced, with the heat of baking in the sun and the harsh environment on the boat it does drip out and water gets in.
Just out of curiosity, so we can all learn, is that why you replaced both of your gearboxes? If so, why would you expect not to have any issues in the future, if you are replacing them with the same thing?
Whether you use gear oil or grease is probably less important than adding grease nipples or access plugs so you can periodically refresh the lubricant and displace any water.
---In amelyachtowners@..., <divanz620@...> wrote :
These gearboxes are "lubricated for life" according to the label. I guess that means that when they run out of life they are no longer lubricated.
An old one that I took off was definitely filled with heavy weight oil not grease.
Oil seems the better bet to me...its a gearbox not a bearing.
Grease tends to get thrown off the gears and sticks to the case, oil on the other hand being less viscous is always in contact with the gear teeth surfaces.
Having recently replaced both outhaul and main furling gearboxes, I hope to never have any issues.