My 83 300D with 212K miles has no locomotion! I was coming off a stop sign,the car began to accelerate,then I heard a loud noise almost like metal sheering off and then the engine just reved over like it was in neutral. Nothing happens when I put it in drive or reverse ,however it grinds when I put it in park as it would if you tried to put it in park while the car is still in motion . Any thoughts on what it could be or how big a job it is to fix would be appreciated .
Dave