The usual like don't put a multigrade oil in as this froffs up and starves the bearings ,you must use mineral oil only , put 86/90 diff oil in as this lubricates everything , yeah so thats why i am a bit hesitance on the gear changing thingy , I think i will take your advise and put the 15/ w 40 or 15w60 in it and hope for the best , thanks for the prompt replies guys cheers TONA 51 590 .