Mohd Saadi

Hello guys,
My car has a rear humming noise that will get loud at speed
So I've read forums that some people pointed to #rear wheels (but unfortunately a member change their tires and nothing happened)
Also they pointed on
#the rear wheel bearing (i went to a local mechanic and remove the rear bearings then spin it buy hand and he said that it's perfect 😂 then another mec came and did the same thing and say it's good, the noise is from the differential
#And the rear differential (I've replaced my own differential fluid + added some treatment but nothing happened)
Finally i went to another mec who use to work to the dealer he picked his doctor headphones and listen to the rear noise and he said that the problem is from the rear bearings)
I did nothing except changing the diff oil
So there's no conclusion of solving this problem
Only 1 member said that he changed the engine and transmission mounts and it works (and I'm not really sure about that)
Almost 10 cars posted about this problem but no one posted on how to fix it (except for the guy who changed engine and tranny mounts)
So if anyone can please help us go ahead
Thank you 🥺

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CaliBenzDriver

Seems you have corned the problem already: rear diff input bearing!

What's current mileage?

Was it already noisy before you serviced the diff fluid?

Mohd Saadi

They want to change the entire differential
90k miles
And yes it was already noisy when i changed my diff fluid

CaliBenzDriver

either a swap or a rebuild kit with bearings including races.
Some people have reported seeing wasted diff oil. It always nice to have a magnetic drain plug to capture steel particulate from gears and bearings... cheap and easy
😃

andynmaas

Rebuild rear diff don't wait soon it will broke transfer case which part of transmission for MB shop will need to replace entire transmission which cost around $8500.

LILBENZ230

Hold up here, you're talking about 2 different issues. I know you're mad at your car but no need in trying to scare others with misinformation.

andynmaas

I didn't mean to scare but the problem if we didn't take care anything related to front or rear differential then later it will damage the transfer case which for Mercedes that good profit because they will only replace transmission. My case is caused by noise which related to driveline and any out of balance problem related to rear/front differential will definitely kill transfer case if not handled immediately. I just didn't like my bad experience would happened to somebody else. Find shop that use vibration and sound monitoring electronic attached to any important part. They can monitor the vibration while car is driven and this is more accurate way to find noise and vibration. The faster you resolve the problem the least impact to transfer case or transmission. You had 2011 W212 which had well know transmission problem which need to open transmission to fix because one bad component. I think the problem resolved in 2012 or newer.

LILBENZ230

I don't see where in this thread anyone said this car is 4Matic. Unless I missed it?

If it is RWD it does not have a transfer case and rear differentials can be replaced independently of the transmission.

CaliBenzDriver

let that Rear Diff be a lesson for overlooked maintenance :

1Qt. Oil change ....vs.... Differencial overhaul Castrol Axle 80w90 @50kMi
😃

andynmaas

You are absolutely right Senecan. I think MB intentionally doing that so everyone will just let go the car after 100K miles and buy new one every 4 year after warranty expired. That why E350 sell new $65K and after warranty expired 40K miles or after 4 year it reduced to around $20K almost 30% of original value. So the first owner got depreciation around $10K per year to have Mercedes Benz. Different with Honda when I had engine blow even the dealer give me choice to get new engine or got used engine. I made choice to use used engine I have to buy myself around and Honda dealer swap it and the car run find for 10 years with used engine. I think Japanese do business with high honesty and German they really didn't care they just want to make profit.

LILBENZ230

Uhh, no. Car dealerships are - universally - part swappers. I've literally owned at least 1 car from each mainstream Japanese/Korean brand. I've had 3 Hondas, 1 Acura, 1 Lexus, 1 Toyota, 2 Nissans, 2 Infinitis, 1 Hyundai and 3 Kias.

The best dealership experience I've had is with Mercedes, but honestly they're all the same. They don't actually "fix" anything. They throw parts - which is fine while you're under warranty but gets out of control when it comes out of your pocket. So I use reputable independent shops for out of warranty work and those guys know how to fix things. We had a rear differential go out in a 2009 C300 (not mine but close family). They'd bought it used from Carmax, no warranty, car was 4 years old and apparently some d-bag improperly serviced the rear diff at a really early mileage leading to its demise at like 60,000 miles. Our independent mechanic sourced a used one, replaced it, did brakes at all 4 corners and belts all for less than Mercedes wanted just for the differential PART not including labor.

These cars are not scary, nor are they necessarily any more poorly designed than any other car. You keep mentioning Honda - are you familiar with Honda's complete inability to manufacture a quality automatic transmission from circa 1997 to 2005? That one Acura I had was a 2002 TL that ate 3 transmissions in 76,000 miles. To have ever properly fixed those cars would have required a redesigned transmission and do you think Honda stepped up? They did not. They extended warranties to 100k miles and that was that.

So Mercedes has not set you up. You have 170k miles and a bit of bad luck.

FYI - the worst dealership/ownership experience I've had was with Porsche. Costs are triple that of Mercedes for no reason and they don't even pretend to care about customers.

YMMV.

andynmaas

I didn't said they set me up but I hate the fact they will only replace transmission as one of member experience they will ask for US$8k. But he instead go for independence mechanic to swap with used transmission so only cost $2500. And most of the independence shop I ask they afraid to fix because they said Mercedes will not sell the necessary part and programming ECU & TCM not that easy. So I have to find Indy close to Dallas or I have to do it myself. You lucky chose RWD instead of 4matic. I did have Honda Pilot 2003 bought used around 2007 and I think I still consider lucky because the famous transmission problem in many Honda is not happened until 270K miles. So far now I had bad experience with Mercedes and not with Honda even though I had the one potentially will had bad transmission.