Ifinally got feed up hearing my deck rattle, it was driving me nuts!!
I traced the noise to be coming from the belt pulley. The movement of the pulley was consistentwith the rattle I was hearing. What I did to fix it, was add more tension tothe pulley by adding a second spring (See Pictures).I purchased the same springused on the deck locking pivot. (P/N M118949). I have cut the lawn twice since adding this spring and the deck rattleis gone!!!!!!