Are you sure? There aren't any M11 sized bolts. It would be unlikely a Japanese built vehicle that uses metric bolts would use an imperial sized bolt in this location. It's possible a previous owner, or other incompetent person, has installed the incorrect bolt. An imperial 7/16" UNF bolt has a diameter of 0.4375" with a pitch of 20 threads per inch. An M12 bolt has diameter of 0.4724" if it has 1.25mm pitch this translates to 20.32 threads per inch.