I don't think one tooth would make a difference.
FYI I moved this to the general C&V forum for you.
OH wait that is a 7spd FW. are your shifters 6 or 7 spd? if they are 6 you need a new shifter. friction nost any FW will work but a hyperglide will shift better
__________________
“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk