C270 Cdi Rumble/ vibration from rear

[Precision Tuning]

Good day all members

I am new to this forum.
I've got a C270 CDI w203 sedan 2003, with 432,000km. I maintain the vehicle myself. The car goes well, no suspension or power issues.
However for the past few months I have been experiencing a vibration/ rumble coming from the rear end, it sometimes feels like the vehicle is jumping along (very slight). The vibration/ rumble also travels through the floor and is felt on the seats.
I started off with the basics. I will list everything I've done so far below. It's driving me pretty crazy at this point. I've checked through the entire suspension, front and rear as well as bushes. The problem still persists despite whatever has been done.

All parts I've changed are from Mercedes-Benz & high quality german aftermarket.

Brand new tyres (Michelin pilot sport 4)
New rims (1 year old)
Road force balancing
Propshaft balancing
Propshaft couplings
Centre carrier bearing & carrier
Engine mounts and transmission
Second hand gearbox from a lower mileage vehicle (changed 2 years ago no issues)
New differential
Front wheel bearings
Front discs and pads
Rear discs and pads
Front and rear shocks (bilstein)

I will Highly appreciate any assistance.

Kind Regards
Hamza

 

[SmartAmg]

Welcome, Hamza.

 

[Taffy7hfa]

Hi Hamza, that's some impressive mileage ! everything is going to be a bit worn though , my guess would be a rear wheel bearing or differential.

 

[Rory]

Sorry, I don't know and don't want to send you off in the wrong direction, but in the UK that car would only be worth a few hundred pounds, if that, so it's a shocking amount of parts you've changed!

 

[mattkh]

Put 2 bags of 10kg sand in the boot on each side and test on a new different route and report back.

 

[Precision Tuning]

Hi Hamza, that's some impressive mileage ! everything is going to be a bit worn though , my guess would be a rear wheel bearing or differential

Hi Hamza, that's some impressive mileage ! everything is going to be a bit worn though , my guess would be a rear wheel bearing or differential.

Hi. Thanks
I will check the rear wheel bearings out. I've changed the differential as well.

 

[napo]

Hi. Thanks
I will check the rear wheel bearings out. I've changed the differential as well.

Any luck mate ?
As I have a similar issue where I changed the propshaft with bearing ,differential, wheels one bearing to front and one to back.
Checked for runout with measuring gauge and everything seems to be fine.
It drives me nuts

 

[brandwooddixon]

Any luck mate ?
As I have a similar issue where I changed the propshaft with bearing ,differential, wheels one bearing to front and one to back.
Checked for runout with measuring gauge and everything seems to be fine.
It drives me nuts

OP hasn't been seen since Dec 2021, it may be worth starting a new thread.