Humming Sound at 7th Gear
I have a E250 W212 Year 2013 1.8 Turbo Petrol. The car belongs to my dad, he no longer drives it. I happen to drive once a while when at home. I recently realized that the car hums when it shifts to the 7th gear. Is that a normal phenomenon. I observe this condition when at high speeds namely >110kmh. Does anyone in the forum experience the same condition as mine? Do advice and provide your hypothesis.
thanks.




My hypothesis is your Dad's shaft bearings dislike oil with contaminated by suspended metals.
Soft ball bearings get irreversible pitted because these fluids are mostly unfiltered. Diff has no strainer or magnet.
Just turn up the radio !
✌️


