Input on Potential Front Differential Issue
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Joined: Oct 2023
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2011 C300 4MATIC Sport
Input on Potential Front Differential Issue
Hey all, my 2011 c300 4MATIC is at 205k and I believe it could be finally experiencing a front differential going bad. Quick recap of work up to this point, I've personally replaced the entire rear sub frame, struts, diff fluid change etc. Now to the front, roughly 5k miles ago, I had to replace a failed right CV axle, so I went ahead and replaced driver side as well. In addition, both front struts and front diff fluid change. I'd say since the CV axle change, I've had a rotational noise, whining/grinding/howling. The noise is constant based on my speed. Its predominant around 25-40mph and its there turning left, right, or straight. No sight of diff fluid leaks. I'll attach two videos for input, one of me driving to hear the rotational noise and another under the vehicle showing a noticeable "clicking" noise at the front shaft to diff. Do I have a failed pinion bearing in the diff? Team, please share your thoughts.
https://youtu.be/iY1taYbkefA?si=lcLJ7ZbJRy_qq0y_
https://youtu.be/-SuzHrJVu2A?si=Fi5XsQxJ2hca8SKP
https://youtu.be/iY1taYbkefA?si=lcLJ7ZbJRy_qq0y_
https://youtu.be/-SuzHrJVu2A?si=Fi5XsQxJ2hca8SKP
MBWorld Fanatic!
Joined: Aug 2023
Posts: 3,737
Likes: 1,135
From: MA Coast
W204 2010 C300 4matic Sport M272
Im not an expert. But if it were me I would drain the front diff and inspect the oil for any metal. Refill with proper amount of Mercedes spec gear oil. I used the Febi 75W-85 GL5 in mine. My operators manual says the front diff holds 1.1 quarts, but only something like .7 came out so that's what I put back in and seems to be running good.
I watched the video and can hear what you describe. I just cant tell where its coming from with headphones on.
have you inspected the intermediate shaft bearing on the drivers side? I recently read someone in a few posts below about a failed bearing and they can clearly look in and see it. That's why I just thought about it.
Sorry cant be more help. But i wouldn't drive around with it like that until fixed.
I watched the video and can hear what you describe. I just cant tell where its coming from with headphones on.
have you inspected the intermediate shaft bearing on the drivers side? I recently read someone in a few posts below about a failed bearing and they can clearly look in and see it. That's why I just thought about it.
Sorry cant be more help. But i wouldn't drive around with it like that until fixed.
Super Member
Joined: May 2024
Posts: 506
Likes: 124
From: Northern Indiana
2014 c300 w204.080 3.5 v6
Sounds like a bad beating so I would consider replacing both front wheel bearings since you took the front apart I would say a front wheel bearing went bad after you installed new CV axles and had to remove add tighten back up the axle nut. They will go bad quick after being messed with it seems.
