I had a problem with mine and it wouldn't go forward. If it moves backwards, it needs to go all the way back before it operates correctly.
The larger part with the spring has to be towards the motor. A very few are oval instead of round and have to be placed correctly to fit the housing.
I replaced my windshield for 200 and they came to my home to do it. 1981 300sd Mercedes
It's the fluid inside the transmission that lubricates the gears and allows the transmission to function properly. It should be replaced with Diamond SPT III transmission fluid.
The batteries are not rechargeable. They must be replaced.
Unscrew them , & repalce , usually only the nozzle is replaced .
Air in the fuel line?? There is a filter in your tank that may need to be replaced.
Most Mercedes Benz Techs will suggest replacing your battery every 7 years.
Break pads should be checked if not replaced. Check condition of rotors at the same time.
This is cluster failure! The instrument cluster will need to be replaced this is usually done by certified Mercedes repair facility
Fuel pump gasket (in tank) not replaced properly?
The owners manual gives a step by step instruction on how to do this.
Normally a timing chain will last the life of the engine and is replaced during a complete engine rebuild. No maintenance is normally required.