I have a 2002 escape 4x4 and it's been having trouble shifting gears, but only on hills. I just noticed this b/c I moved from California to Connecticut and there's way more hills out here. It'll downshift while it's going up a hill (to get more power??) but it'll go up to like 3000 RPMs then vibrate and shift up again. I dont know if its the transmission or what. I just had the transmission fluid changed and that helped a little but there's still a problem. Any ideas as to what the problem might be? | 
