I'm having tranmission problems with my 95 e320 which has 114k miles on it. Yesterday while on the freeway, I kept a steady speed at 80mph. when out of nowhere, I feel the car drop down a gear or two and see the rpm fly. I change lanes but I can't really press the gas pedal because of the gear it's on and the speed the car has, so I try to coast it to an exit. As soon as I get off, it stays in that same gear and doesn't change until I come to a full stop and then go. What's going on? Is it time for the transmission to get tuned up? Thanks in advance.

 

When you stopped and then Go, does this mean you turned OFF the ignition? Did this procedure clear the problem? It is now OK again? If not what are the current symptoms?

 

I meant like got off of the freeway, came to a red light, (foot on brake, waiting for light) then I drove and it acted normally. This also happens if i'm in heavy traffic on the freeway and it's stop and go, when I go, the car doesn't engage the gear...No symptoms. This only has happened on the freeway, if I'm driving +60mph for more than half an hour.

 

Right.
Now I understand more clearly this looks more like a mechanical (temperature) rather than electronics issue.
I have (fortunately) never encountered any transmission problems so I have no expertise in this field.
However, have you checked the transmission oil level?
I understand that this is not as easy as it sounds. I am not conversant with the detail procedure.
Is the box still filled with OE oil or has some other brand/type been put in. It appears that the boxes are very sensitive to the oil spec?
Advice on this forum seems to suggest that changing the oil (which according to MB is filled for life - without specifying what life is!) is a good idea at about 100k. Sounds like good advice if the correct oil is used.
Hope it turns out to be something simple.

 

Well, I checked out the kickdown switch, unplugged it and then plugged it back in, and so far so good. As for the tranny oil, it is OEM and I don't think it's for life since that idea started for the 1996 models..and up.