What would make my truck make a quiet, fast paced ticking ONLY when moving? It doesn't do it when idling or revving in park, neutral, or any of the drive gears with the brakes on...

 

U-joints can cause strange noises when they freeze up, but there is usually a vibration also.

 

Vibration while moving or while turning? Sometimes either at high speed or very low speed there is vibration on the front end

 

I'd jackstand the rear end and "drive" it to see if it is the front or rear.

If it isn't the rear, look at the dust shields for the discs. You can jack each front side and spin the wheels pretty fast by hand to try to recreate the noise. I'd jack from the lower A-arm to keep the weight on the suspension while spinning the wheel.

 

anyone thinnk it might be a rock or a nail in a tire? it is possible. Check your tires.

 

could be a wheel bearing also

 

Maybe your brakes are shirpping since they are worn?