My man! you need to replace the BB, there is no reliable way to service your BB.Unfortunately SRAM or any other company makes it nearly impossible to R&R bottom brackets.The main reason I run Shimano Cranks is that the BBs tend to last longer.cheers mate!

 

lubricant - How to properly clean and lube the bearings on a sram apex bottom bracket (GXP)? - Bicycles Stack Exchange

 

Typically these are sealed bearing units - they are in no way designed to be taken apart. They will run rough after a certain period, and you replace them

 

I would think you would need to remove the BB and submerge in mineral spirits to get them clean. If they are rough it's probably too late for a service - the balls and races are likely damaged. The new grease may make them last a bit longer but a new BB is in your future.

 

I know ppl don't like to spend money, but, a new GXP is about $30. And, it should last a few thousand miles and more if cleaned regularly and not abused. Thats really not that expensive. Or, get a Chris King or Enduro Fork Seals GXP for more money and they are serviceable in one way or another.

 

this..

and you can pick up a park tool BBT-19 for about $20-22 US. i don't usually buy from my local bs.....but i do try and spend some $ there, more than i'd pay online, just to support em so long as it's not a big ticket item. support - like charity - usually begins at home

 

you can clean them,.. but if they are "grainy " feeling you'er probably already beyond cleaning as SRAM uses a rather soft ball material... but if you do re-grease even bad ones will run smoother,.. for a time.

the key (oh I hate this part) WD-40.. yes yes.. we've all been warned about WD-40 on bikes but in this case it actually helps.. also will need an air compressor.

one remove outer seals and such.. you can expose one side of the balls.. clean out as much as you can like you did with a degreaser .. issues is now.. you can't get all the old grease OR all the new de-greaser out. :madman:
well, WD-40 will (help) remove both. just use the little straw and blast between each ball.. wipe then do the next one (if you just blast away you'll push the dirt around and not get it all out)..

once done with that. blast with air ...

use a decent grease and pack it in there..,, DON'T WASH out the WD-40, most is blown out with the air. (ya ya.. there will be the rocket scientists telling you to remove it ) the thing is the WD-40 WILL thin the new grease.. but.. with older bearings that you are one sided packing it's a good thing as it helps distribute it more evenly .. yes the grease will break down faster being thinned a bit.. but you're bearings are likely going to be completely toast long before you break it down enough to worry about.

other tips..

with GXP cranks I HIGHLY recommend cleaning out the bolt and threads on the non drive side as much as you can.. that interface of the arm/bolt/non-drive side bearing seal/race is what makes it better than the side loaded style like Shimano.. but.. if dirty it can screw up fast and mess up everything.

 

Good tips, thanks!

The BB retails for over $50 here in Canada and I dont buy online (I have a very good relationship with my LBS) so it is up to the guy there if he wants to give me a discount (he usually does).

But if I can clean it for free I'd rather save the money.

 

oh, one other option.. get a ultrasonic cleaner.. can get them for under 50 buck (probably even in Canada) take the seals off and throw it all in the machine and let it do the work..