I have a slight leak developing through the seal on one side of the rear diff. Nothing major, just a sweat, now covering a small portion of the casing below the joint. It is nothing new as there has been some staining on the joint for as long as I can remember but seems to be getting worse over the years and many 1000s of km...

I have scheduled the rear subframe bushes replacement sometime in September and thinking of having the diff seal replaced while at it. My question is, should I replace all three of them or just the offending one? I mean the other ones may or may not be too far behind. But the failing one took years to get at where it is right now so I wouldn't want to fix something that isn't broken...

Diff oil was changed less than a year ago.




The sheen on the shell is due to a thorough wipe.



That's where the oil comes from.

To wrap this up: Changed the oil seal on the leaking side only. Couldn't spend a holiday month worrying over this... Now, it also seems we have inadvertently sorted a minor knock which we always assumed was from the subframe bushes. I might not have to replace those, not this year, if that's the case