Has anyone had this issue before?
Had my first chance to get under the car properly and all looks pretty goodexcept for the rear diff housing.

It's incredibly rusty. Dragged up from the bottom of the sea flaky rusty!

No evidence of leakage yet but it looks terrible. Should i be budgeting for a new rear diff?

MW

No sir, quite normal

Make sure the fluid is good though as it degrades quickly!!!

Well thats a relief! Thanks Craig.
I'll do the fluid, and the whole car will be treated to a Rustmaster treatment later in the year, which should arrest any further deterioration.

MW

The diffs only have a coat of thin paint thrown on them when new, they're made from quite thick cast steel so would take decades to actually rust through i would think.