All,

Have a 82 300SD w 104K miles.

Driving home yesterday on the freeway (60MPH) and suddenly the car acts like the tranny is in neutral and the speedo pegs at 100MPH. Coast off the freeway to safe spot. Try all gears, no go.

With the shifter in D rev the motor and see the odometer clicking off tenths of miles. So, the engine is turning something in the tranny to drive the odometer but not the car. Look under car, driveshaft still there, flex joints look OK. When shifting back to Park, shifter gets stuck but am able to shift to L and then to Park. Grinding noise after shifting to Park for a couple of seconds.

Have searched the archives and although not the same symptoms, could this be a B2 Piston?

If not, have a tranny from a 79 450SEL, will it sub for the 82 300SD tranny?

Thanks,

JV