My b170 was having a bit of engine vibration during acceleration from 0-40km/h or some time at 60-80km/h. Secondly, when turning to the left, there is click click sound at right wheel. After i consulted to many sifu, came to conclude that it was right/driver side drive shaft problem. Both inner and outer CV were in bad condition. Inner cv causing the vibration and outer CV causing click click sound when turning left.
Come to the solution, there are 3 options. 1st: buy original new one rm3600, 2nd:get a used/recond one rm850-rm1300, 3rd:change original outer cv joint only rm1200. 3rd option immediate dropped because not solving vibration issue. 2nd option i think may not worth because drive shaft is wear and tear thing, not lasting. Finally i choose the most pocket damaging option to buy a new original shaft.
After replaced by city cycle ah beng (labour is cheap :)) , all my problem solved, i am happy driving again. I have no regret to choose most costly option
Another sharing is new original drive shaft already improve over old stock one. I can find the inner and outer cv of new one much bigger and heavier. The new driver side drive shaft part no is A169 370 56 72. My old stock drive shaft is A169 370 12 72. I have seen some where forum saying due to stock one not lasting, mercedes had improved the shaft few times.

i was told by city cycle Ah Beng that DO NOT fully turn the steering and drive aggressively when taking corner. this will stress and damage the drive shaft especially for any front wheel drive. To taking care on this, the shaft will last very very long.

Photo is here (old one upper, new one lower):


new drive shaft A169 370 56 72:

...

Thanks for sharing Bro!