I'd be very grateful for any advice and/or opinions. After 8 months of piddling I finally got serious about getting my '71 250 on the road. After a couple of days of sorting the disconnected shifter linkage, replacing the brake calipers, pads, rubber hoses, and flushing the lines I was ready to take the car for a ride. Car will start and idle. It will shift into and through the gears with the shifter, but it will not move forward or backward. The transmission fluid was low, about 2 quarts, but is now full. It smells burnt. Is it likely that my transmission is toast? Could this be the result of towing the car, without disconnecting the drive shaft, with a tow dolly about 30 miles? Although we put the car in neutral, it somehow jumped into gear as some point and had to be returned to neutral manually during the trip.
In General to tow In neutral is OK but not advised . For a short Tow say 15 25 Miles the Key is Speed ! if the Tow Truck go's slow like 30MPH and Under most likely no Problem . Mercedes with rear wheels Turning cause the rear Pump to turn . This is a Good thing However.
To go a higher speed could cause the car to drop in to gear and if fast enough then the motor well turn over ( if free )
30 Miles is about the limit I would tow without disconnecting the drive-line and I would keep the speed as low as possible . What you do is tow from the rear but you know that now . You just turn the wheels straight and tie the steering wheel to the Wing Vent pillar.
My Guess is that the Transmission is toast, pull the pan to confirm .
If you see a lot of Gunk and Metal as well as Burned fluid most likely in only 30 Miles the transmission was already not so great .
Moreover It's about the speed , if you towed at 50 , 60 the transmission would be damaged after 30 Miles most assuredly since it dropped into gear.
somehow I don't think this helps but who knows just a opinion