In this video, This Old House general contractor Tom Silva explains how to muffle a noisy garage-door opener.
1 Unplug the motor of the garage-door opener.
2 Place stepladder under garage-door opener motor; set wood block on top of ladder.
3 Unbolt and lower motor from mounting straps; set motor on top of wood blocks.
4 Disconnect door-track mounting bracket from wall.
5 Place rubber pad behind mounting bracket and reattach it to the wall.
6 Hang the motor from the mounting straps using rubber pads.
7 Remove the stepladder and wood blocking.
8 Test the operation of the garage-door opener.