4.5 Diff Whine?

[vroom]

Hi All,

Just after a bit of advice.

I 'think'my diff may have developed a bit of a slight whine but it only does it at exactly 70MPH otherwise it's silent above and below this speed. Does it regardless of temp, selected gear etc.

Any ideas? Could it be a CV joint or even propshaft? Diff oil was changed about 7K ago but I'm planning to change this very soon using the correct Morris oil.

Any ideas?

Or is just nature of the beast. Other than this it's very smooth with no horrible noises.

Cheers

Nick