i'm trying to overhaul my bottom bracket for the first time but i have come across an odd problem. i have two crank pullers, one is just too big and the other only fits on to the left crank arm. can't figure out why. it is a square tapered crank with the old style bottom bracket not a cartridge type. both the arms are original, matching and havent been replaced at any time.

so my question is this; is it still possible to do bottom bracket maintenance without removing the right side crank arm???

ive been looking forward to this all week and i cant go out and buy a new puller because i can only get them online which takes a while and my guess is that a third crank puller wouldn't fit either.