Drivetrain grinds when in reverse

[mercisbest]

I have w124 e280, and every time I put it into reverse, the final drive starts to grind for a few minutes then stops.
Does anyone know what the problem is, and how to sort it.
Cheers.

 

[Bigtee]

Does this only happen in reverse?

Have you any oil leaks? checked the level? any play in the front bearing (pinion)?

What is the mileage etc?.

 

[Myros]

it could also be

engine mountings, although they tend to show up when put in drive, rather than reverse.
Have a look at the radiator fan.( engine off) is it sitting square in the middle of the cowl. if it has sunk down a bit, then the engine has dropped as the engine mounts have compressed.