I have a circa 1977 Maytag A-206S. I love this machine and take great care of it. The top seal under the agitator is like new with no leakage and the agitator comes off with no effort. The question I have is this: how often does the oil in the transmission need to be changed? I am sure that the grease in it is original from the factory. Is there anything I should expect from a machine of its vintage? I am very fond of this machine and want to keep it going for awhile, or until I find a matching A806 set with the sudsaver (I wish) . Any info would be appreciated thanks guys, Derek