Oil on rear brakes

[Parazine]

I am no authority on the ideal level. There have been very extensive posts on and someone can hopefully refer to. The main thing is that never allowed to run really low and dry.

For decades my RP was maintained full but not without problems. The first suggestion of a lower level I read in an old NZ VAR mag where it was recorded that Len Southward used to advise. Pre war Len ran a business specialising in Seven maintenance, but is now remembered mainly for the world renowned motor museum he later established.

I usually go for about 1/2" - 3/4" below the filler plug level. The exact level doesn't matter too much, the key point is that the oil level shouldn't be above the half shafts, otherwise it will leak down the tubes. All of the differential components get covered in oil film and that provides the lubrication necessary.
For regular servicing, just check that the level is maintained and as Bob says, the axle mustn't run too low.