Le Mans back axle differential cover - right way up ?

[Joanymalony]

Hi

I have been filling the back axle with oil and it struck me that I might have the diff cover on the wrong way around. The bolt holding the cover on are equally spaced so it appears that it could be easily done.
There are 4 threadedplugs on the casing and cover. The one on the top of the axle casing is the filler and has a narrow breather pipe. The one on the bottom of the casting is the drain plug, I get that.
Presumably one of the other two is the level indicator where oil comes out if an attempt is made to overfill, but what is the other one ?
If the plate is on the wrong way around the axle could obviously be over or under filled.

Any help with this would be much appreciated.

Thanks

David

[telco.2]

Yes it's upside down. The oil level will be too high & you'll get oil on the brakes