Thanks for the info guys, I will check the noise again tomorrow, useful tips. I have had wheel bearings go before, and normally they quieten when turning the steering wheel. These bearings I believe are the wider type, probably needle rollers, and the noise is constant when steering either way. That is why I suspect the diff bearing, but as I said it is only a slight hum at certain speeds at the moment, and I am hyper critical. I did notice today that the nearside tyre has worn on the very inside edge, unusual for the Fiat, also a sign of wheel bearing wear I believe, or tracking but that was done very recently, and I am the only driver and have not hit any kerbs recently to put it out. I will not do the job myself, but do like to be informed on how much work is involved before taking it to a specialist. I am usually hands on, but lately with the cold weather I think it best if I let someone else do it. When a vehicle earns a living, I certainly don't want it to be in bits for very long lol.