Truck was due for inspection (didn't need anything, truck has 68K on it, brakes and tires were done about 10,000 miles ago) needed tires rotated and had them service front and rear diffs and transfer case while it was in there. Gear oil and transfer case were OE, I bought the truck in Jan 18 with 9400 miles on it, so I know it hadn't been done. One of those, I'll get to it, but never got to it deals. They charged me $59.50 per axle which I thought was very reasonable considering I was looking at having to buy 5 quarts synthetic synthetic gear oil. Also had them do the transfer case. Left the shop and had to make a 25 mile drive. I swear, by the time I was on the way back (maybe 40 miles on the fluid swap), truck was a lot quieter, partly because the tires were rotated (fronts were getting some noise) but also differential was noticeably quieter. Guess it just goes to show, for the $120 spent , not really any excuse to not maintain fluid changes. Trans is next, see when the weather warms up how ambitious I feel.