Is there any way of relubing a Shimano Hollowtech 2 BB? When I got it, there was shimano snot grease all over it, so I'm thinking either the seals aren't 100% or it was just left over from assembly.

Is it possible to pop open the seals and smear in some fresh grease now and then, as with some sealed bearings, or am I just meant to throw them away when they go all pitted and dry?

There was lube on mine when I got my new crankset as well. I believe it's left there to prevent corrosion during shipment/storage of the parts. I just wiped the external surfaces with a rag, put some bearing grease on the threads, and torqued it to spec. Once you use up the bearings order up a ceramic kit and pop them into the cups.

Mike

They can be serviced somewhat, but you have to be careful with the seals and the plastic spacer. Try this thread on mtbr for servicing info https://forums.mtbr.com/showthread.php?t=136309

Leave it alone and just ride. I've got sealed BB's with up to 10 seasons of my miserable winter rains and mud that have been not only ridden in this muck but also (carefully) cleaned with soap and brush and gentle water spray. The BB's are all still going strong with not a hint of mysterious noises yet. In fact they are getting BETTER with age rather than worse. My single speed spins the cranks backwards for something like 5 or 7 turns from a gentle pedal tap.

Unfortunately the op indicated he has the outboard bearings of the Hollowtech II BB. I dont think they have been around 10 years. I do miss the old heavy, well sealed un-# type but we must move on, mustn't we.

That grease was left over from assembly. They inject it into the partially assembled bearing sets until it oozes out to make sure no crud gets in.

Unless the bearings are making noise and/or running rough they are just fine.

Go ride.

Oh, they are fine just now, but I'd just like to know, for future reference. An ounce of prevention and all that... I repack my hubs before anything goes wrong, then there's no damage to the races. Once grit gets in, or water, it's all downhill, but with regular servicing they can last ages. I just wondered if the same was true of the new BB's, or if they are just disposable like the cartridge BB's. I don't like disposable stuff.