95 Rover County drive train

I have a 95 Rover County with drive train problems. When I back it up, or when I make turns to the right and left
There is a fierce ‘clunk’ sound in the rear end.

  1. I first noticed black fluid appearing on right rear wheel, in a spin pattern indicating an axle leak.
    I replaced that axle seal.

  2. Within a few months, a fierce clunk happened while backing up, rover mechanic drove it and diagnosed it as rear pumpkin.
    Rebuilt the pumpkin, used old housing.
    All work so far has been done by competent mechanics.

  3. CLunk re appeared. A new Rover master mechanic at LandRover garage diagnosed it as some kind of “friction clutch” that comes after the transmission.
    I don’t really understand this part. He says the misdiagnosis of rear pumpkin as cause of the sound is a common mistake.

However this diagnosis doesn’t make sense to me, how does something in the drive train before the u joint cause a noise when turning, both while going forward or backward when wheels are turning at different speeds? No other buddy mechanics can make sense of this either. As the part alone is 3,500 dollars from Land Rover, I am hoping there is another cause and solution.

Many thanks for any feedback or input on this. I really like this old rover. It is a wrk horse par excellence with trailers, or loads or difficult terrain.

Rover Blues