I got my hands on a record 10 speed gruppo as part of a bike that was in Hurricane Ike. I'm attempting to recover the gruppo to throw on a cross/winter bike, and I've cleaned them out as thoroughly as I can without disassembling, sprayed the guts with gt85, re-cleaned, and lubed them. The front shifter works great, and the rear also works great with the exception of the fact that it sticks in the highest gear and wont' shift back toward the low cogs.
Any idea what would cause that? Is there anything in the shifter's internals that could be toast?