hello, i have an AMERICAN YARD PRODUCTS REAR TIME TILLER, SOLD BY CO-OP , MODEL # TR500, THE MANU. ID # IS TR500K. HAS BAD TRANSMISSION IN IT. I NEED A MANUAL ON IT AND A PARTS BREAKDOWN. ALSO, WHAT YEARS WAS THIS TRASMISSION USED IN THESE TILLERS. MINE WAS BUILT IN 1998. I NEED A PARTS BREAK DOWN AND PRICE LIST. ALSO, WHAT OTHER COMPANIES USED THIS PARTICULAR TILLER? PLEASE ASSIST ME IN THIS ENDEVOR. HUSKAVARNA SAYS THEY CAN'T HELP, AS IT IS TOO OLD. THANK YOU, WAYNE EULER