Before I bought my car many years ago I got several issues of Merceds Enthusiasts magazine buyers guide for C36 and C43.
The articles mentioned that C36 from MY97 fitted with the very first 5 speed electronic transmission was prone to have major problems and so did the C43 from MY98 to mid 99 before tiptronic was released for MY00 which was the improved stronger transmission.
Most problems with these trannies happened from a slipping transmission losing gears.
Once I lost drive coming into a sharp left turn at a stop light, I passed on yellow when I had to stop but I was too lazy to stop so I floored it!
On the main road just after the sharp turn after the red light I had to straighten the wheel and all of a sudden I lost drive, transmission didn't want to engage for several seconds.
I don't know what happened just at that moment why my car didn't want to drive forward?
After a few seconds it all went back to normal again and transmission working OK.
Last year I had an oil service with filter and pilot bush replaced.
I told the specialist to drain the pan and complete TQ then he flushed the system oil lines through the oil cooler until new oil was coming out.
This is the proper way of changing oil.
Dealership only drains the pan and lets the TQ keep the old dirty oil to mix with the new oil from the pan.
New oil gets dirty very quick.
No good!