I've noticed a certain noise under the pedal area on my '04 SR5 V6. When I go up a hill under wet conditions, I feel some type of movement under the pedals followed by a shifting, grinding, then twangy noise. Something is obvioulsy moving under there. It only happens when I go up a wet hill (pavement). Actually, it also happened today when I went DOWN a small hill and hit the brakes. Anyone know what's going on? Thanks!