Just finished with changing my rear differential fluid (used Mobil 1 75-90W) Put in 1.5 qts. I searched in a couple places and saw that most people used the Mobil 1 (or another brand's) bottle and were able to squeeze it into the top hole for filling, but it was very tight and prone to spill out. I used a 3/8" clear air hose (at Home Depot for under 10 bucks). Put one end into the top hole on the differential (after draining the bottom plug) and cut the Mobil 1 bottle's tip so it would fit the hose. It helps to have one person hold the bottle and squeeze while you hold the other end of the hose into the differential. I had left over hose from what I didn't need for when I use for my Fumoto oil valve (w/nipple) No spills, no tight spots, super easy! And I didn't have to buy a pump!

Changed at 12,423 miles, it was starting to get a little sludgy but not bad. Had a couple shavings but that was it. Glad I didn't wait any longer to switch to synthetic! (I've heard all sorts of stories of people changing at 18k, 24k and 30k and having tons of metal shavings!).

I can post pics tomorrow if that helps anyone

 

I used the same method!!!!! I do get tons of shaving at 15K and 30K.... Thinking bout changing at 40K again.

 

What differential fluid are you using?

 

Valvoline full syn 75w-90

 

should get some royal purple - it has the limited slip differential additive already added. You guys have been adding the limited slip fluid in addition to the fluid you have been adding right? Assuming you have a car that has a limited slip of course.