Steve,
While I had my Steamway Sidekick, a smaller TM, I know, however, I had to replace the pump drive belt. This meant splitting the drive to the blower. I moved the engine back, removed the rubber drive coupler, and slid it through. Moving the engine back was simple enough, but meant uncoupling some rigid parts, like the exhaust pipe, and a couple of hoses to the heat exchangers etc. Took about an hour.
Dave.