I own a KitchenAid mixer (model #KP2671XMC) which I purchased on 10/18/04. It has started leaking oil/grease into my batter. My husband and I removed the piece that attaches to the head to find quite a bit of grease/oil in it. We then removed the cover to the head and believe the oil/grease may be leaking from the housing unit. Perhaps the gasket is damaged? Is there any other reason oil/grease would be leaking from this mixer? And if this is correct, is item #AP4308824 (items 7 & 31 housing) the correct item we need to order from your site? thank you