Mixfinder -
I may be imposing by answering a question to Andy, and if so, please forgive me. Belt-drive transmissions seldom truly 'knock' unless they are VERY worn, but they do, especially when healthy, make a good loud clunck when first engaging agitation. This is the spring loaded agitator gear engaging the agitator shaft.
There is a 'gear fork' inside the transmission that raises and lowers the agitator gear into and out of "gear". As it wears it moves around a bit during operation and can create a rythmical tapping sound, especially when the transmission is not under heavy load. This is nothing to worry about. The snubber and snubber plate can also cause a knocking sound as the snubber plate can get loose in the plastic tub ring. This can be moderately annoying actually.
But, I didn't notice a transmission noise when I saw Andy's video this morning. I can't play it at work, but will do so again when I get home.
Interestingly, I was wonderig the same thing about Andy's detergent - they have incredible water pressure, but the water I'd bet is pretty hard.
Gordon
