Pinion oil seal

[muggwump]

Just been told that my diff is leaking oil past the pinion oil seal. How easy is this to change and what is the process?
Any special tools required?

[Mogwai]

If its an early diff the pinion will be shimmed so the nut can just be retorqued. later ones have a collapsable spacer this will need replacing & the pinion preload reset

[bmcecosse]

Unless it's a serious leak - just ignore it and top up the diff from time to time. Worth checking that the breather (on top of diff casing) is clear. Maybe the nut that secures the drive flange has worked loose - worth checking.