My tranny is feeling real wierd lately. The car itself feels more sluggish. Today in 5th gear on the highway my car was making some weird noises. When I would get off the gas you would hear this horrible grinding noise and the when I pushed the gas it would take a second or two but then it would grab and keep going. I am also getting a vibration in the car in the lower rpms and at about 75-80. What could it be??? Do I need a new tranny??