c270d loud whine from drivetrain

[Tonedef]

Hi.
Hope someone can help. I recently bought a 2002 C270 auto diesel saloon with 160K on the clock. Really enjoying it until yesterday when driving along motorway. Car gave a judder then started to whine loudly from the rear somewhere. Managed to drive home and car seems ok on a light throttle but as soon as I come off the accelerator the noise returns. It also whines loudly as I accelerate from a standstill up to about 35mph then the noise nearly goes completely.
Can't feel any play in the rear wheels when jacked so pretty sure its not wheel bearings but it is a bearing kind of noise.
I'm just hoping its not a replacement gearbox or rear diff job!!

Any ideas??

 

[Steve@Avantgarde]

Difficult to say without hearing it but I would say its a possible diff or torque converter failure.

 

[BABASON]

Check propshaft bearings carefully

 

[Tonedef]

Thanks.. I've booked it in the local garage for Tuesday but they're not Mercedes specialists so it will be good to have a few ideas of what the problem might be.
I'd like to try and narrow it down a bit before I go to the garage. Is there any way to test propshaft bearings, torque converter or diff without having a ramp or any computer diagnostic equipment?

 

[Tonedef]

Thinking back to when it first happened there was a judder then a loud whine. Then there was a spell for a minute or so when after I came off the accelerator completely the car would then begin to accelerate slightly . Quite worrying at the time but then it settled and I forgot about it.
Could I be right in thinking that this might point more towards the torque converter as I can't think how the diff or propshaft bearings failing could have caused this effect?
I am heartened by the fact that no one has suggested gearbox failure!!

 

[television]

I think pinion bearing in the diff, they normally whine when pulling and silent in the over run, but if a bearing broke who knows

 

[Tonedef]

Thanks for the help.
Turned out to be the diff. Managed to get a used one for £140 on e-bay. Fitted for £120 by local garage.