I recently was coming up the backside(East) of Stevens Pass when the tranny shifted to a "New" gear. The truck has always sat at Approx. 1800rpm @ 60mph and out of the blue it dropped to 1500rpm and had massive power! I have not seen this since I have owned the truck(04 since new). I did get it to do it one more time on the freeway after stabbing the throttle to the floor and letting completely off, but can't get it to do it again. Any ideas???

 

not sure ya found a new gear, od l/u maybe? next time out try lifting the brake pedal lightly with your toe and see if it happens.1800 is 70 in mine but it's much older.