rear differential fluid level below fill plug

[Ronzxcvb]

I'm servicing a 2000 Yukon rear differential and it states in manual plus there is a blue warning label on the rear differential that it should be only filled to about 1/2" below fill plug
I did a search looking for the capacities and it looks like everyone just fills them up to the fill plug
Does anyone have the capacities for the rear differential by glove box code?
How likely is it that it will cause a seal to leak or something else to go wrong by overfilling it by the 1/2"?

 

[Ronzxcvb]

good news the dorman differential cover with fill plug is at the proper level
I made some gauges out of pipe cleaners

 

[jj_nycguy]

I have to say, I am guilty for filling them up until the fluid spills out and capping it off. Never had an issue but I probably should fill up to the manufacturers recommendation.

 

[ISU-152]

I've always heard just fill to where you can touch it with your pinky finger

 

[Ronzxcvb]

John that's the way it was done for years this is something new (at least to me)
I am thinking that they had alot of differentials made for using regular gear oil when they switched to using synthetic thus the weird filling instructions