driving my 2008 w204 c300 4matic sport with 168000 Miles on it i recently while driving in downtown San Diego during our.latest storm encounter, i hit a pothole then some steel plates(same day) that were not properly placed by the construction company currently building a 45 story high rise apartment building. Anyways i hit the hole and plates both hard (35 mph) and immediatly once i reached the freeway began to.feel something similar to the vibration that you feel when you get one them huge.sidewall bubbles.on the.inside of one of your tires. Pulling over.on the side.of.the freeway to take.a.look sure enough I was relieved to see.that indeed was.the case. Huge.bubble formed on the side of my front driverside.wheel. say relieved because i could fix.that easily with a.quick tire.shop stop. On the way home ˙tire eventually blew out luckily within a mile.from my drive.way but unfortunately 5 miles from tire shop. Making it home I needed to install all four stock tires and load up the one to take it to the shop. Upon doing so I discovered that I actually needed all four tires as each one had a.identical.2"x1/4" gash down to the wires just along the inner beed of all 4tires. No worries just further puts my mind at ease that the vibration was indeed the result from my tires unbalanced and not something mechanical. So got my 19s loaded in the car and my like new stock 17s on my car and began to continue on over to the tire shop. pulling out the driveway and before i could even pass my neighbors driveway/house, sure as **** I start t o feel the same slight grinding then a thunk. I parked it put it up on 4 6ton Jack's about 2.5' feet high jumped I the driver seat and turned it on and put it in drive and what I found was that front passenger and rear driver were spinning as they should however front driver and rear passenger well front driver would spin then at almost full.rotation would began to.start.pivoting while.rear passenger would.barely if any at all ĥave very lil rotation with unless I would give it some load I. Which case all tires would spin up until rear passenger would start to pivot at almost full rotation. However no slight grinding noise just the clunk which seemed to come from the front. Next I went ahead and using my hand began to slowly give it gas in which case all tires would began to spin until I reached just below 20 rpms and although several rotations without clunk suddenly the slight grinding began followed by the clunk.

I've removed front drive axles driver/passenger to check if possible cv damage may be the cause or wheel bearing etc... no change..So.i.drained differential no metal visibly seen in the fluid .next removed drained transfer case, fluid was filthy but no metal, removed tranfsfer case and after thorough inspection , aside from being alarmingly dry and some stutter aas a result from the old burnt up atf gunk that formed under the bearings over the past 15,years, otherwise all my tranfer case parts are in well enoigh condition to eliminate as the cause. Iam however unsure about the u joint inside the front axle shaft and intend on replacing only because mine appears to bei. Pristine condition compared to the ones ive seen that show signs of failure. I also have not been able to find any further information pertaining to my experiences so I'm not even sure I'm heading in the right direction as far diagnostics. I've also inspected.flex.disc.and drive train and from what I observed not enough to going on there to be the cause for the slight grind before clunk issue. My next attack will be on the differential unless any better or the actual problemca. be identified.

Any advice, guidance, or feedback welcome.
much obliged.
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Hi Alupnrguts. I hope this helps.It seems you're encountering a complex issue with your vehicle after hitting potholes and steel plates, leading to tire damage and drivetrain-related symptoms. The troubleshooting steps you've taken, such as inspecting the differential, transfer case, axles, and u-joints, are commendable. However, if the problem persists, it might be beneficial to perform further diagnostics and potentially use a diagnostic scanner to read any fault codes stored in the vehicle's computer.

Given the complexity of the situation and the variety of potential causes, seeking professional assistance from a mechanic or technician with expertise in Mercedes-Benz vehicles might be advisable. They can conduct a comprehensive inspection using specialized tools and diagnostic equipment to accurately pinpoint the underlying issue.

Additionally, accessing repair manuals like the YOUCANIC pro repair manuals could provide detailed OEM procedures for troubleshooting and fixing drivetrain-related problems in your specific vehicle model. Always prioritize safety and seek professional help if needed to ensure the proper diagnosis and resolution of the issue.