Just changed oil in rear differential and the amount of oil drained out not near what I put back in. Quart and a half out and three quarts back and absolutly no evidence of a leak anywhere. The owners manual tells me what oil to use but not amount. This is a 2000 yukon with 80,000 miles that i have had for about four months. Tag on the differential suggest a level to maintain- 15 to 40 mm below fill hole (not real easy to determine). So the question is... What is the fluid capacity of the rear differential?