I would fit them dry or with dry PTFE spray because grease in this area will collect dirt and grit grinding the collars and springs away over time.
Eric
that is what I was thinking really, I checked the official workshop manual and it indicates (by omission of any instruction) dry assembly, I think this is correct in that the spring isn't intended to slip on the mounting. I just thinking really about protecting the rubber from perishing I might put a light coating of ptfe spray just on the edges after assembly.
