I would be interested in how you get on with this Chris, because I think min needs to have the preload and/or back lash adjusted also.

How many miles has your car done and what makes you think this is required on your differential?

My car has done 105000 miles (168000km). It doesnt really make any noise except for a slight whine at low speeds, however the car has always had a slight looseness in the drive train that gives a slight knock in some situations and I think this is from the diff.

But I decided not to worry about it, and 20000 miles with it like this and no problems, its not getting any worse. But if there was a simple fix I would be interetsed.

good luck!