Good idea. The lawnmower is of course built around the transmission, so removing it is a bit of a hassle.

What I'll probably do is replace the easily replaceable parts (key, spring, clamps, washers, gear), give it a good lubrication, and sell it (disclosing the worn part) and replace it with a battery-powered mower. I'm tired of dealing with gas machines. I'm under no illusion that a battery-powered mower will be as durable, but I'm just done with the noise and pollution of gas.