it's more like a glue rather than oil ...

I think it's almost impossible to get all these tiny bubbles out of the 500k diff oil.
Filled up the housing til the pinion submerged ... then filled the rest up with 100k, which is a lot easier to handle ....

tried to heat it up with a heat gun ... didn't help that much ...
I guess it would help if heating it up in boiling water before filling the housing.
Viscosity should change if temperatures get in that range ... at least is that what I learned from my google research

now the housing stands on my central heating boiler the next 20 hours ... guess the little bubbles need some time to make their way out there ...