I have a mtd 136m667f118 14.5/38in riding mower. my deck is tilting towards up in the front hitting the lower engine pulley when the deck is in the highest blade off position sending the sparks flying. Is there a spring or some adjustment that holds the back part of the deck up and level..I can lift the back of the deck about an inch in the back and everything is level and the deck does not hit the pulley. It seems that the adjustable lift link is unbalanced and bias towards the front no matter if I adjust the link up or down. It's an older machine but new to ma and soon to be the son's.