Anybody here fill theirs to the hole opposed to volume. I always filled my LR3 open diff this way (despite what the manual says) and never had an issue. Seems to be a hot topic. Did the same with my LR4 but this has a locking diff and now am paranoid.

 

The volume of the diff is clearly written in the manual. There is some reasoning that should the casing be overfilled, that the oxidation/foaming of the fluid results in poorer lubrication.

Old school, use the fill port as a fill level.
New school, don't.

I'm just happy to hear to changed out the fluid... many don't. Then complain about the whining diff. Then replace it.
Of course old school thinking would be to rebuild it... where are those skills now??

 

To the hole. There is little difference. The reason for the spec is because first, they need to specify an amount and second for fleet environmental numbers. Consider the spec pretty much the economical minimum of fluid as a large corporation sees it.

 

I filled mine to the hole, all good as far as I can tell.

 

Previous owner had it serviced at the dealer its whole life. They said they fill to the hole. Case closed.