I grease mine every year at least once. Mine mushroomed over too. I chocked mine on my buffer wheel shaft and used a bastard file to cut it flat then hit it with some 2000 grit and carnauba wax. Up and running.
it's been ages since I posted that video; for the speed feed head, I ended up replacing the sealed bushings on my Stihl trimmer head. Despite being told they don't go bad and getting funny looks at my mower shop, that has resolved the issue of melting that plastic bushing the speed feed headed uses. First attempt was re-greasing the trimmer head, but that did not work. new bushings did the trick. Ran my unit hard this year with 0 issues.
