Shimano Bottom Bracket

chillibeer

Dear internet,

I have a 2009 Spesh Stumpjumper Elite FSR and have enjoyed a full year of carefree riding. However, I took part in the Chain Reaction Cycle's Marathon two weeks ago in a mud bath. I went through my usual cleaning routine afterwards but when I went to take my bike out this weekend the bottom bracket had seized. I rode it round the block a few times but this hasn't free'd it up.

The bottom bracket is a Shimano FC-M542. Can these be stripped down and cleaned or will I have to buy a new one? Any help or advice would be appreicated.

Cheers

ma9mwah

Seems to be a standard hollowtech2 external bottom bracket. Shimano do have a 'do not disasemble' warning but a few people say they've been successful in removing the seal and regreasing. But even if it's gone to far for that then a new one is only ~£17 from CRC

UncleMonty

I strip down my FSA external BB to clean & de-grease, take your time - you don't want to damage the seals, I used wooden tooth pick the fist time but now I know how it comes apart I use a very small srewdriver and my finger nails.

diy

Or warm up the grease insert in a syringe and inject it in leaving the seals in place..

but since its likely to have gone rusty I would replace it.

nicklouse

mm grease that get thin when warm..

no thanks a constant viscosity is best as it will not thicken when cold.

edjo

"no thanks a constant viscosity is best as it will not thicken when cold"

all greases thicken / thin depending upon temperature; the oil within the grease changes viscocity as it is cooled or warmed.
HOWEVER, warming a grease to inject it as mentioned above is unlikely to be effective as it won't thin that much.
pop the seals, scrub with some solvent / brake cleaner and regrease...if this doesnt work, CRC !