Wheel bearing oil and rear end

Hi Guys,
I have a leaking cover that needs to be fixed...( Wheel bearing on the trailer )
Before I mess with it I want oil on hand.

If my memory is any good...90/140 should work in the Wheels and the rear end on the truck.

Any thing I need to know ?

I don't like to work these much until I've checked the oil levels...

even the ones not leaking.

Thanks for any advise.

Gotta Fly...
JAM View attachment 171848 View attachment 171849 View attachment 171850

Wheel bearing oil and rear end