Abstract: A directional drilling tool permits the control of the angle of drilling of a drill bit through the repeated placement or removal of a ball within the mudstream. The ball activates a clutch mechanism within the directional drilling tool. The clutch mechanism, upon activiation, locks the exterior of the directional drilling sub to a fixed angular orientation. Simultaneously, there is activated a deflection mechanism to deflect a drive shaft which is normally fixed in an aligned straight position within the tube body, so as to shift the normally straight aligned shaft to a deflected position, causing the bit and the sub to angle for drilling at a controlled angle of offset from the vertical. The unit is aligned and located using wireline measuring equipment of known design.