Got a Gravely 152 w/ 28 hours. Today the drive belt came off leaving the mower undriveable. I noticed a big black spring came loose as well. I got the belt back on the pulleys and the idler pulley and the spring back in place. I start the mower and after about two seconds the belt comes off and the spring comes off too. Its going back to the dealer in the morning for repair. Anyone else had this problem?