Do you fill the diff fluid right up to the fill hole or no?

 

yes until it starts to dribble out

 

Need to do mine, first time. What fluid should I use?

 

in the owners manual it will tell you what fluid.

but i use 80w -140 (or something like that, I cant remember off the top of my head)

then if you have an lsd or basically anything but an open diff a friction modifier is used

 

I always use SAE 80W-90 GL5

 

I always use 85-140, the heavier you use the quiter your bearings are and the longer they and your gears will last

 

Don't have an owners manual. Where is the best place/brand? Thanks

 

I need to just top mine off both are low

 

What about transfer case I got the fluid what plug do I take out to fill?

 

Top plug I take it?

 

sub

 

The 8-W-140 is designated for use with the towing package - dunno if any gear parts are different than the stock diff so can't be sure using the higher viscosity is a good idea or not. I'd be a little careful in the colder climes where it might be less effective.

 

Do you have to use tranny fluid for transfer case?

 

you use ATF for the tansfercase dextron III.

and the gears are not different the 85-140 is meant to be used for heavy applications, towing, offroad, ect. I always run it 100% of the time without issue

 

This is odd. Chrysler 8.25 has a rubber plug in the cover. How am I suppose to fill that rear end? I figured there was a bung to unscrew