Yale door locks comply with building industry standards and fit into factory-machined and bored doors. When replacing an ordinary lockset with a Yale product, however, the hole in the doorjamb that accepts the door latch may have to be drilled a little deeper. This is to allow space for the guard bolt fitted to Yale locks to extend its full free length. The trickiest part of installing a Yale lockset is aligning the lock unit housing, but this is easily accomplished by following the step-by-step installation instructions.
Insert the latch unit into the pre-drilled and mortised hole in the edge of the door. Position the unit so that the curved face of the latch bolt faces toward the closed position of the door, with the flat bolt face vertical. Press the oblong mounting plate into the pre-cut mortise so that the plate is flush with the edge of the door.
Press the point of an awl into the two countersunk screw holes on the latch mounting plate to make a starter recess for the screws. Clamp a screwdriver bit into the chuck of a cordless drill/driver. Insert the two countersunk screws provided in the kit and tighten securely.
Measure the depth of the hole through the strike plate fitted to the doorjamb with a steel engineer's ruler. If the hole is shallower than the latch bolt, unscrew the strike plate screws with a Phillips screwdriver and deepen the hole with a suitable drill bit and cordless drill/driver. Replace the strike plate after doing so.
Remove the inside knob from the lockset. Insert the pushpin provided with the lockset into the small recessed catch situated on the side of the knob mounting shaft. Press the pushpin inward to depress the spring-loaded pin. Slide the inside knob off the spindle. Remove the round ornamental plate or "rose" and the inside retainer plate situated between the inside knob and the lockset.
Adjust the lockset to match the door thickness. On a 1 3/8-inch-thick door, the gap between the inside face of the outside rose and the inside lock unit must be 1/8-inch, and the gap between the rose and the lock unit on a 1 3/4-inch-thick door must be 1/4-inch. Rotate the outside rose in or out; set the clearance gap with a steel engineer's ruler to match your door thickness.
Slide the lock unit from the outside of the door into the round 2 1/4-inch-diameter hole pre-drilled through the door. Slot the lock unit spindle through the hole in the latch mechanism protruding in from the edge of the door. Depress the latch bolt on the edge of the door slightly. Wiggle the handle back and forth until the lock unit slides home and the front rose fits flush with the outside of the door.
Slip the round inside retainer plate over the lock unit spindle so that the attaching screw holes are vertical. Insert the two machine screws provided and tighten securely with a Phillips screwdriver.
Slide the inside rose onto the lockset. Line the notch on the inside of the rose so that it fits over the spring clip attached to the mounting plate. Press the rose home until you feel the spring clip snap into place.
Line up the slot inside the shank of the inside knob with the knob catch on the spindle. Press the spring-loaded catch in with the pushpin while pressing the inside knob home. You will feel the spring-loaded catch snap into the slot when positioned correctly; this will hold the inside knob and prevent it from being pulled off the spindle.
Open and close the door a few times to test the action of the latch mechanism. Insert the key into the lock from the outside. Lock the door to ensure that the locking mechanism is working properly.