Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hello,Checking the fluid level and condition is definitely required before disassembling the gearbox. Reading out the fault codes from transmission is also necessary Although, electronic faults will cause only limited and rough gear engagement. The total loss of frictional connection can be caused by excessive play in the output shaft.
It can be adjusted by removing the propshaft connections and installing additional shims. I have seen such adjustment solve the symptoms you have described.