Having just purchased a Westerly and joined the Westerly Owners Assocaciation I think the answer has to be yes. There is a lot of information on the WOA website http://www.westerly-owners.co.uk/ and I would sugest looking there. In my own case the boat needs osmosis ttreatment and while she is out of the water I intend inspecting the splines. From reading the WOA newsletters and from their forum on Yahoo it is much easier to drop the gearbox off and check than fail when you need the push.