Introducing myself

[JamesNY]

Greetings one and all!
James NY here, owner and amateur driveway mechanic of a 2008 C300 4Matic sport w204 and 2015 ML400 w167 with M276 engine

 

[JamesNY]

2008 C300 W204 4Matic. I have been experiencing a noise whose loudness varies directly in proportion to the revolutions of the front wheels when under load. To describe the noise, it is similar to the “gear whine” heard when a manual transmission German car is put in reverse. It emanates from the center of the vehicle between the front wheels. I’ve ruled out wheel bearings as there is no noise from the wheels when turning, and the wheels spin smoothly and quietly when up on jacks. At speed, shifting into neutral and coasting eliminates the sound. Sound was first noticed following front Right (passenger side) CV axle replacement to deal with a torn boot. I suspect I damaged the front differential carrier bearing when I ham-fisted the new axle back into the Front diff. This sudden new noise lead me to suspect I had a faulty axle from the manufacturer. I returned it, and replaced it with a new axle that clicked nicely back into the front diff. Unfortunately, the gear noise remains, leading me to suspect I’d damaged or displaced the carrier bearing when I replaced the axle the first time.
I’ve had an Indy mechanic in the vehicle for a ride, his opinion was the problem was in the Front diff perhaps the pinion gear. Another Indy took a look (in their shop) and quoted me $7k for a new tranny, as they believed the source is the power take-off (aka transfer case). Before i consider discarding this vehicle, I’d like to remove the Front diff and replace the bearings and seals, as my gut tells me that’s the source of the noise.

Can anyone help direct me to the procedure for removing the FRONT differential
I can detach and remove front L&R half axles. My problem is twofold: firstly, how to access and detach the driveshaft, and secondly, how to access the differential mounting bolt that is tucked behind the frame? I presume there is a special tool or ratcheting wrench to fit these mounting bolts which are E-bolts rather than hex head.
I have searched high and low for a procedure or an online video tutorial, but to no avail. It seems there is scant repair info on this vehicle outside; I’ve inquired at the Mercedes dealer if I could purchase a shop manual from them and they told me they do not sell them. Any help is much appreciated. I live in upstate NY.

 

[A.J.]

Hi James, welcome to the best forum out there Unfortunately I don't know a right hand spanner from a left hand spanner but there are plenty on here that do

 

[00slk]

Hello and welcome,
Possibly you have damaged the inner bearing?
There should be a knowledgeable chap along shortly with the rest of your question.

 

[Blobcat]

Hello and welcome

 

[PaulG]

Welcome etc the forum James

 

[JamesNY]

Hi James, welcome to the best forum out there Unfortunately I don't know a right hand spanner from a left hand spanner but there are plenty on here that do

Lol! Thank you PaulG

 

[JamesNY]

Thank you all

 

[PaulG]

Lol! Thank you PaulG

It was Andy who said that.

 

[SmartAmg]

Welcome, James.

 

[JamesNY]

It was Andy who said that.

My mistake, I was a bit clumsy with my reply! I meant to LOL to Andy’s humorous spanner reference! Thank you for the “heads up”