How to Replace the Mounting Assembly in a Garbage Disposal

Unplug the disposal power cord from the electrical outlet in the sink cabinet. Skip this step if the disposal is hard-wired.

Turn the power to the disposal off at the circuit breaker in the main breaker box. Hold a no-touch electrical tester to the disposal wiring. Continue if the tester indicates the current has been turned off. Twist off the wire nuts where the wiring from the disposal attaches to the building electrical wiring. Twist the wire connections apart with a pair of pliers. Skip this step if your disposal has a power cord that is plugged into an outlet.

Loosen the large nut that attaches the drain pipe to the disposal with a pair of locking pliers. Hold the bottom of the disposal with one hand while using the other hand to loosen the locking ring on the underside of the disposal with a flat blade screwdriver. Lower the disposal from the underside of the sink and place it aside.

Loosen the retaining screws that attach the disposal mounting assembly to the underside of the sink with a Phillips screwdriver. Pry off the snap ring that holds the assembly to the sink using a flat blade screwdriver. Lower the assembly from the bottom of the sink and remove it from the base cabinet.

Push the disposal mounting flange up from the bottom of the sink and remove it from the top side. Carefully scrape any plumber's putty from around the sink drain with a flat blade screwdriver.

Form a 3/4-inch thick rope of plumber's putty with your hands. Apply the putty around the edge of the sink drain from the top side. Insert a new disposal mounting flange into the sink drain from the top and press it into the putty. Have a helper hold the flange down against the sink until the new mounting assembly is secured.

Slide a gasket and mounting ring onto the underside of the disposal mounting flange Push the new disposal mounting assembly into place on the underside of the flange. Push a new snap ring onto the bottom of the assembly until it snaps into place. Tighten the retaining screws on the bottom of the assembly with a Phillips screwdriver.

Install the disposal to the new mounting assembly in the reverse order of removal.