OK so i found out some info on this push rod update, from what Branson told me this was not a true recall, what happened is they had about 50-100 of the 15 series model tractor ranging from 30-48hp have some push rods that weren't properly heat treated from a run at the beginning of this year at the factory because of this they issued a part update bulletin for the affected engines, basically if you haven't received a letter from Branson about this your tractor is not affected. as for the noise me and the head mechanic here have given ourselves grey hairs trying to find the source of this rattle, from everything we checked out we can't seem to locate a source of the noise and it has no effect on running performance. - this is cross posted from another post i made