Thanks for the ideas. Don’t know why I never thought of silica gel, as I use it in the cupboards of small tools. Clutches will be on shafts so will tie a bag around, or something similar, I find the bags stay working for a long time, over a year anyway, in my very damp w/shop. I was hoping there would be some sort of spray-on substance, what do car makers use? These things are built up maybe 2 years, then sent round the world, often as deck cargo, without the clutch or brakes etc corroding.