I have a 94 jeep grand Cherokee. When driving your hear a low grinding. When pulling into a parking spot after driving while it almost feels like something is gonna snap if you keep going. Could this be wheel bearings? Or something else. Also she. The air or heat is on it blows out a musty odor and it won't blow out the middle vents. Just the floor and top vents. Any ideas? Help greatly appreciated it has a 4.0 engine. Thanks everyone!