Originally Posted by
Andrew R Stewart
This type of seal, not rapped by a outer sleeve or groove, is often found to travel as it stretches/expands with wear. One more reason that the marketing term "sealed" is not what many find is the real result. I see a lot of pedals and other bearing units with drifting/expanding seals often.
I disagree with the suggestion of too much grease being a wrong thing. Seals are about keeping stuff out of a bearing, not about keeping grease in. I feel one should grease a bearing so some grease gets squeezed out in initial use.
Again I think the failure here is the belief that the "seals" referenced are a positive and reliable barrier to stuff getting in. Andy
It was not my intention to imply that there was too much grease, simply that the purging is the likely culprit. Shimano specifies a 1/3 fill inside the pedal body, which would, as you noted, purge grease during the initial use.
For my pedals, I've often noted a displaced seal that refuses to stay in place; the grease inside does not seem terribly different from the other pedal during my 6-12 month checkup period.
FWIW, OP, you can take that part number on the exploded view to any bike shop with a Shimano account, and order a replacement part.