Well, I think it's time I tear into it and see what is wrong. The knocking seems to start earlier and earlier everytime I use it. What I'm looking for is any insight that might make it a little easier. Any input on troubles I might run into, any special tools I might need, any tricks or tips you might have before I start. I have the service manual, so that should help, but still would like to hear any advice. By the way it is a TM20.