I have a late 1980s John Deere with a 46" deck exactly like the one pictured. The double pulley at the rear has developed a forward lean to it. So much so, it's wearing out my belts rather quickly, with me buying several each of the last few seasons. These decks are a little hard to find, it seems I can never find one close to me. Anyone else dealt with this problem or have suggestions to fix it?