W202 1998 C280 Transmission problem - Please Help

at I have, because it is not my original language.This is my first post her= e in the forum.I have a MB W202 C280 Sport USA version M112 engine . a few = weeks I have it stopped by a strange problem in the transmission.=A0

weeks ago the car did not perform the shifting and had a strange humming n= oise, but that happened only once. We took it to the mechanic and said it w= as an electrical problem and had cleaned the sensors and it works (do not k= now what sensors) . They also suggested we perform the change of the transm= ission oil.We made the oil change and after that the car no longer worked. = But the strange thing is that if you run the car in the morning works perfe= ctly for approx. 30 minutes making gear changes beautifully, after those 30= minutes stop shitfting and remains as in limp mode with that strange hummi= ng sound.I thought I had not sufficient amount of transmission oil but I ha= ve the meter to check. so I take chances and add 1 quart. more to test but = does the same.once the vehicle is cooled again fully operational for 30 min= utes.

e ID151 gear comparision incorrect and code ID 147 gear implausible or tran= s.slipping". Also the differetial pinion seal is leaking and needs a transm= ition mount.

If your Mercedes is a 202029 chassis it has a 722.6 transmission. Common pr= oblems are the electronic conductor plate atop the transmission valve body = and the transmission control unit. The electrical connector at the transmis= sion frequently leaks trans fluid into the trans wiring harness and eventua= lly into the control unit. No easy diagnosis here. Take your Benz to the ne= arest Factory authorized Mercedes-Benz Dealer where they can properly diagn= ose the problem and give you an accurate estimate of repairs.

Thank you for the reply,

I did the same thing what you have been told me and the estimate that the transmition it should be replaced... that will cost me aprox 5000$ :/ What now?