Transmission problem
 

I have a problem with my transmission. I left a restaurant, was sitting at a traffic light, hit the gas pedal, ......and the car wouldn't move.

I manually downshifted to 2nd gear, and the car started driving seemingly at normal acceleration, then I had to upshift to 3rd and then into Drive gear.

When I got home, the car wouldn't shift into Park. I had to put it into Neutral and turn it off that way. When the car was off, then I could go the whole way up and put it into Park.

I tried it all again, and same thing, so it wasn't a one-time thing. The good thing is, the car does drive and does go in reverse, so if I need to go to a transmission shop, I can at least drive there.

1991 300d, 195k

Skip the shop and save $1000. Probably the plastic "shift bushings" have fallen apart. Search that here. Many posts. You get at them underneath, one at each end of the horizontal "shift rod". Fun part is there is little room to work and it is probably very grubby. I recall the youtube video (Ken of Mercedes Source) shows a 1986+ 300D and he had to drop the engine slightly to get room or at least to see w/ the camera. I bought the special pliers, then found I needed to add a washer on the rear of it.

Not the plastic bushing
 

No, I've had the bushing problem before. In that situation, the shifter starts to rattle a bit then eventually gets worse and prevents you from shifting. The car can go into Drive, it just ....doesn't go anywhere.

To the best of my recollection being able to shift into park is a governor problem. It might have popped out of its bore. I remember that happening to me.

This thead has pics of the home made shifter bushing tool.
http://www.peachparts.com/shopforum/diesel-discussion/355592-shifter-bushing-tool-problems-fix-1985-300d.html

See post #2. I copied the Pics from another Forum member.

There is indeed a hydraulic lock out that stops you from selecting reverse (and then park of course) when the transmission thinks the forward speed is above <INSERT SMALL NUMBER> km/h

So if it is this then there's possibly a governor / valve body related problem.

However as suggested by others I would not rule out a shifter or shifter bushing problem

Other basic things such as fluid level and fluid cleanliness needs to be considered.

A fluid and filter change might be enough to make a positive influence - however these days with the silly cost of fluid I'm less inclined to reach for fresh fluid!


If there's nothing obviously wrong with the transmission from the outside inspections then the hydraulic pressures need to be measured - a problem with the governor for example should be evident from measurements.

(Much better to measure than to use the force Luke)