Ok here it is, I bought an '83 venture royale late last summer rode it a few times before I had to put it up for the winter. Now that summer is almost here again I decided to change all the fluids. My question is how do I know how much "final gear" oil to use? Read in here somewhere that in the toolkit (mine is long gone) there was a device for just this sorta thing. Like I stated mine is long long gone. So do I just fill it up or ........ Thanks in advance.