My transmission is giving me problems yet again. The first time was about 8k miles. The Dealer replaced some bands and tighten things up. Then at about 12k miles, the transmission goofed up again, I received a low power warning. The Dealer replaced cracked servo valves. Now, at 43k miles, I am experiencing problems similar to the earlier problems. The tach bounces up and down as the engine speed goes up and down. The gas mileage has tanked. Also, is it normal to be on a hill, truck in "D," and have the truck roll backward like it is in neutral when you take your foot off the brake? When I step on the gas, it takes a second or two before the truck stops rolling backwards. It is almost as if I let the clutch out. But this is an automatic. The Dealer is of no help.