hey PJ my new 52 inch super mini is giving me some problems,last week the blades starting a high pitched whinning noise. and then the blades would not engage. the dealer replaced the idler pulley and the pto switch. but the noise is still there and the blade speed is not the same as before, they checked the spindles and said they were fine but the noise is still there and it seems to be coming from the discharge side of the deck. mower has 160 hours. please help they are not sure what is wrong but are trying to help. thanks in advance. TN MAC.