It was time to change the differential fluid (was instructed to change it after running around 500 miles with the new gears) so snooped around a bit and landed on Amsoil Severe Gear 75W-140. Problem was no body carries it but luckily found a little Amsoil stand inside a truck stop right across the bridge in Portland... Kubitz Truck Stop. Picked up 6 quarts on President's day.
Rear was pretty easy to drain since it has a drain plug... uses a 3/8" drive (no socket). The diff shop used red loctite on the threads so it was a beaoch to get out. Had to hammer it loose and managed to get the old oil drained. It was a light purple when they filled it but came out a dirty, greenish color. Opened the fill plug in the same manner and got a little new oil in there to flush out a bit more of the old oil. Getting the new fluid in was also a beaoch! I bought a hand pump when I got the oil, like what you would get on a hand soap dispenser but larger.
It had a screw top to secure it to the container of oil but it was too small for the Amsoil top... so I'm laying on my back, under the car, it's freezing in the garage, one hand is holding the clear plastic tube from the pump in the fill hole while the other hand was reaching back over my head trying to pump this really thick oil up and in while trying to not dump the oil over. I didn't have much leverage to pump the pump so I'm straining and pumping and my arms tired after only a few pumps. Switched hands a few times and kept going. What worked best was to actually lift the oil container with the pump up and pressing the top of the pump handle up against the frame to get the pumping action. I could do this with two hands while still keeping the tube in position. Took about 2.75 qts, give or take. Phew!!
Going to tackle the front tomorrow but bought a drill pump from Home Depot with a few thread adapters. Hopefully that goes smoother. The front doesn't have a drain plug so I'm just planning on sucking it out. We'll see how that goes.