Originally Posted by ryansu

I recommend a complete tear down and that means overhauling all the bearings (wheels, headset and bb) One thing I will say is keep everything even if you plan to upgrade, When you get the bb out and cleaned up take a good look at the cups. if they seem in good shape you can simply put in new bearings and grease, if the cups are pitted then a square taper sealed unit isn't too expensive just be sure to research what size of sealed cartridge BB you need for your crank and bb shell - which on that trek is almost for sure 68 MM wide. The mytenspeeds website referenced above has an excellent section on bottom brackets - removing, overhauling replacing etc. Since you have been riding the bike think about anything aside from the crunchy pedal that has caught your attention, otherwise plan to thoroughly clean and then lube all the working parts checking for wear - broken sprocket teeth on your rear derailleur etc. I assume you will replace the chain and freewheel, bar tape, tires and tubes, brake pads cables and housing etc i.e the consumables.