NordicTrack E4400 Treadmill Service Call in South Portland, Maine.
This was just a general service, clean, lube, adjust, checkover and diagnose any issues.
As many treadmills, especially many NordicTrack treadmills, the deck must be folded up, locked in place, and then the whole treadmill laid back down to expose the underside of the motor compartment to get at the four screws (see blue arrows in image below) so that the motor cover can be removed.