rcd

I have a 2001 Cannondale T800 touring bike that needs some bottom bracket attention. It's developed a "click" whenever the cranks turn, but only under pressure. I've had the problem occasionally before, and it's been solved by going to the LBS for a BB overhaul or (with luck) adjustment. Given the bike's age, I thought I'd try my hand at it. But before I get started, I'd like to understand what's in store (I've done BB years ago on now-obsolete mechanisms), get some good instruction specific to the BB I have, and make sure I have all the tools. The crank appears to be attached with a bolt requiring a 5/16 hex wrench to remove, but I need to know which way to turn this very stuck bolt. Also, access to the bracket itself appears to require a splined tool, but I have no idea if I have the correct size. There are SO MANY good generic BB instructions on the Web, but I'm not sure how to find one specific to my BB. The bike's age doesn't help! I'd love to be able to find out what (if anything) I need in the way of tools, ride my bike to the LBS and purchase whatever, then come home and do the job. Can anyone help, please? Thanks

AnkleWork

Hmmm . . . that BB is likely a cartridge (as the new bike had a cartridge). No overhaul or adjustment, just remove & replace. Fortunately they are cheap. It's probably Shimano, thus only one removal tool size available. BTW, that "5/16" is actually 8mm.

But how do you know the BB is at fault? Diagnosis of clicking is not so straightforward. R&R is a wasteful and failure prone diagnostic method.

rcd

I'd be surprised if it were a cartridge, but I surprise myself a great deal with what I don't know! Which has to do with why I asked on bikeforum. Maybe someone else here can tell me if it IS a cartridge, as that would simplify things. I have taken the bike in at least twice over the years, asking that the click under load be diagnosed and fixed. For some reason, I was always under the impression that the LBS adjusted bearings or repacked/replaced them (and never for a great deal of money, which suggests it wasn't a cartridge replacement?)
I've had the bike up on a stand numerous times, but can only get the click under load -- much as previously.
Thanks for the 8mm correction. When I apply some torque, 8mm will probably work better than 5/16!
I don't understand your remark about R&R and wasteful, but I DO think throwing a bunch more money toward fixing a 13-year-old well-ridden bike is wasteful. Thanks for your ideas.