9" Gear oil

I am getting ready test drive the XJ with the new ful-widths, and the last thing I have to do is fill the dif's up with fluid I know how much the HP44 takes but can anyone tell me how much I need to pick up for the rear. Dumb question I know, but I am lazy and I don't wanna run to the parts store more than once tomorrow. thanks -steve

Not quite 2 quarts of 75-90, or 80-90.

I'd run 85-140w in a axle, 80-90 is a little too light for the hot days, or long drives.

New gears too? You're gonna have to dump the oil after the first few hundred break in miles so buy plenty. Just pick up two of the gallon size jugs.

How about draining the 9". unbolt the 3rd member? I'm looking in a oil suction pump that is advertised to change engine oil, tranny fluid, and/or coolant.

Im going to use dino oil for the break in, drain the hard way, and then run synth and forret about it forever...or untill I have to cross water.
My other solution is to cut a hole in the top back half of the nin inch housing and weld in a really big nut (like 2" ID) and then use the appropriate bolt with an o-ring for a plug. That way I can check for water contamination/mechanical damage, and I can use a suction pump pulling straight up rather than snaking a tube through the fill plug. I could also aim the tube at the lowest point in the housing.

i was told that i needed to fil it up to the drain plug like a dana axle, that's going to be more than 2-3 quarts I'd guess.

We use Sweptco moly gear oil in all our 9's. It is quite spendy but well worth it. We have also run the mobil 1 syn.