Changing Transmission Fluid in ML 320
I'm changing the transmission fluid in my inlaws ML320. The guy at the dealer sold my father 8 liters of fluid. I told him to get 6qts, but the guy said 8 for the differential. I was planning on draining the pan, torque converter, and replacing the filter. I'm confused what they mean by differential. I was planning on not touching the differentials. From what I could tell, there are 3 differentials in that car. Front, center, rear. I noticed at least the front and center have a drain plug on the bottom, and fill on the top. Is it good practice to replace the diff fluid when the trans fluid/filter is changed? Which ones should I replace the fluid in? When filling the diffs on these cars do you just fill till it spills out the fill plug?