could it be the 15mm tool (socket or peanut butter wrench) have too thick a wall and you are getting interference from the crank? Sometimes you have to lathe or file down the sidewall of the socket to fit in there.
Also, if you are beyond that point, the washer may not be attached to the bolt and still may be sitting in the crankarm- pull that out with a flatblade screwdriver.
--
Tom Martin
General Manager
VO Imports
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