I have a 1998 C280. When I was driving it about a week ago, the engine stopped putting power to the wheels. The engine just revved. It happened while I was driving and the car was moving. I pulled over and had the car towed. When the mechanic looked at it, everything was fine. No codes, the car shifted into gear and drove like nothing ever happened. I picked the car up and drove it a couple of days. This morning, it happened again. I turned the car off for a while and tried to get it to go, but no luck. I could hear a quiet rattle when shifting back in to park. I have had no transmission issues until now. It hasn't made any noises or slipped until now. Any ideas?