Re: motorguide noise
Pull the prop off and see if there is anything behind the prop, IE: fishing line. Also, run it with the prop off to see if it makes noise with the prop gone. A dinged up and out of balance prop can cause the TM to make odd noises.
The bearing/bushings can be replaced, but you have to pull the motor apart. You'll want to replace all the seals if you disturb them so it's water tight after the repair. There are several places online that have TM schematics and parts. Probably a $30-40 repair if you are handy.
FYI, the magnet housing is clocked and must be installed the same way it was removed, mark the housings before taking the motor apart.