I've Got One!!!!

[Bonzo]

Well done on finding a donor James

Looks quite a tidy motor too

As TT said, the Sierra diff is quite robust, I have only ever changed 1, that was on a former Taxi that was on it's 3rd time round the clock.

When it was stripped, there was no signs of heavy wear & probably only needed a bearing or two.
At that time it was no problem finding a good used diff, so it was swapped just to be rid of the anoying whine