Since new my transmission will make the whole truck shudder downshifting from seecond to first. It's as if the the band or clutch (or what ever is responsible for 1st gear ratio) is rapidly engaging and disengaging. This will occur for about three seconds at speeds decelerating from about 5mph. I think this only happen whens the truck is costing down. In other words, if I'm stepping on the brake pedal, this won't happen.