Hi, I have searched for an answer to this on the forum, but to no avail.

My mechanic, with 40 years Mercedes experience is baffled right now.

But he cannot put it up on the lift for another week and half (or more probably) because he has 9 cars ahead of me. The car is outside his shop, and takes some effort to get it up his ramp and into warehouse/garage where the lifts are.

So I figured I would seek out any advice, to make his diagnosis easier.

I have a 1987 420 SEL with a used transmission installed about 3 months ago. It has shifted very smoothly for those 3 months, and I have been very happy with it.

I was traveling on the interstate at about 80 miles an hour, when all of a sudden the car was not in gear anymore, no acceleration/ it was as if I was in neutral.

There was no warning, no horrible sounds. No sound at all.

I managed to coast over to the side of the highway, and sure enough no gears would engage, not even Reverse. I could shift to all those positions, but it just behaved as if in Neutral.

When I tried to put the car in Park, you could hear it ratcheting for a few moments, but when I got out I noticed the car was still acting as if it is in neutral. I could roll it with ease.

Mechanic said he checked it for fluid, and yes it has fluid.

He said he tried shifting, and said there was no "load" when you put it in Drive or Reverse etc.

anybody got any idea what is going on?

thanks in advance.

 

Had a similar problem have your mechanic check the shifter!!! Yes I know this sounds crazy however if the transmission was working right before and there were not sounds, grinding, clunks it appears that the transmission doesn't know what gear to go into. The transmission is mechanical and electronic.

if you had the work done at a transmission shop take it back there.

 

alright, the mercedes W126 transmission is what I call a hybrid. Meaning it depends on electronics to control the vaccum to shift and ye it also depends on mehanicals to. What is sounds like that that something is maladjusted. aka, the shfter cord is not in sync with that gear the transmission is in. This can happen when the bushings arounf the the poit where the shifter cable connects to the transmission wears out or also happens when a new transmission or neutral safety switch is installed and not adjusted correctly. Usually one of two things happen which is either the car cannot or slips out of park and or, the car is constantly betwen gears which, the vaccum portion takes and translate as not in a gear or neutral to prevent damage.

The w126 transmission is one precise piece of equipment and is finiky with the adjustments.


My 560sel did the same thing once after getting a neutral saftey switch replced and come to find out the mechanic forgot to replace and I forgot to tell the mechanic to replace the bushings, so the car couldnt stay in park and the transmission had no idea what gear to be in or what gear it was suppose to be in, aka in between gears.

 

BlackWolf said it very eloquently and technicality. I hope you take the information to hart because I am sure some people have sold their transmissions and or cars because they thought they had a bigger problem then it was.

You know how some shops treat us MBZ owners, its like we have more money than intelligence.