B7510 mmm noise

[JimWool]

I have a B7510 manuel with 8 hrs. When the mmm pto is engaged and I push the clutch in there is a noise from the deck that sounds like gears gridding, it can also be heard when the mmm pto on the clutch engaged and rolling backward it might even be a little worse then. Is this a normal noise? the dealer says it is. They said it was the belt slapping.