My sprocket carrier has become loose and is vibrating (left to right) when spun.

I know I have those little donuts for the cush but I'm thinking a bearing in the carrier, which is part of the cush, is actually the culprit. Any Dymag users out here? Is this a DIY repair?
Also, my Penske shock is leaking (not weeping). It was "serviced" earlier this summer for a similar problem but is leaking again.

Is a Penske better serviced at Penske (in PA)? Or does Speedzilla have a preferred shop close to Cleveland, OH?
Thanks for your thoughts.