E39 530i driving me mad

[JD2329]

I've had the clutch and flywheel replaced the last couple of weeks. Since the car has been back there is a low frequency thrumming coming from the back of the car, only when in gear, worse under load. It's not loud but there is obviously a problem there. It's worse when driving from cold, and comes on between 60-80 mph. Upwards of that speed it seems to go away. My mechanic inspected the driveline for wear when the prop was dropped to replace the clutch and passed it all OK. Going away in two weeks for a Euro road trip and now getting concerned! Anyone who has any ideas or had similar experience, advice very welcome.

[tgr]

Differential?

[The Stiglet]

tgr said:

Differential?

You'd think so.

Does it make the sound if you have it in neutral and let it freewheel down a hill? If so, maybe a wheel hub?

[Frances The Mute]

As above, pop it in neutral when at speed. If it still does it, it's a wheel bearing.

Hopefully it will be as it's the easiest and cheapest job of the two.

[JD2329]

The sound goes away when freewheeling so looks like diff/maybe driveshaft(CV joint?)
Thanks for the advice.