I read in some other thread (forum?) that sometimes new trucks are shipped from the factory with low fluids. I got my new GMC D/A home last thursday. I checked the trans fluid and found that it took 1 quart of fluid to bring it up to the middle of the Hot check area on the dipstick. It was right at the bottom of the hot mark when I first checked it. I then looked at the rear differential and found that it was also low - I couldn't reach the fluid by sticking my pinky finger in up to the second joint. I decided this was too much and called the dealer. I spoke with one of the tech's and he told me to bring the truck in. I asked if I could bring it in right away and he said "sure". I was there in 20 minutes. He checked the rear diff and found it to be about 1/2 quart low. He also checked the transfer case and front differential and they were OK. Word to the Wise.