When replacing a door deadbolt, it might be necessary to adjust the lock's backset. The backset is the distance between the edge of the door and the center of the lock hole on the door. Most deadbolt locks have an adjustable sleeve to accommodate the two typical backsets found on exterior doors drilled by the manufacturers. Failure to adjust the backset results in a lock that does not operate properly or at all. Adjusting the backset ensures the deadbolt locks completely once you install it in the door.
Measure the distance from the edge of the door to the center of the hole with a tape measure. The backset on a dead bolt lock only has two positions. The measurement is either 2 3/8 inches or 2 3/4 inches.
Place the latch plate of the deadbolt lock in the palm of one hand. Find a small lever either on the side of the latch bolt casing or on top of the casing.
Hold the lever up with your fingers while holding the latch plate in your other hand. Slide the dead bolt sleeve away from the latch to set if your door requires the 2 3/4-inch backset. Slide the sleeve toward the latch plate if your door requires the 2 3/8-inch backset. You will hear the sleeve click into position.
Continue with the rest of your dead bolt installation according to the instructions that come with your brand lock once you adjust the backset.