It happens, but they're easier to tear down and repair / rebuild. Main problem that occurs in a manual is the synchronization gear mechanisms going bad (so you

It happens, but they're easier to tear down and repair / rebuild. Main problem that occurs in a manual is the synchronization gear mechanisms going bad (so you have to do the 1940's double de-clutching to manually synchronize), actual wear on the gears being worse because you can actually grind them, and clutch replacements (they are a wear part - essentially a giant brake pad between the engine and transmission).