Step-by-step fix
Step 1: Make sure a deadbolt replacement is the right fix
- Unlock and lock the deadbolt several times with the door open.
- Close the door and try the deadbolt again without forcing the key or thumbturn.
- Check whether the problem is in the lock itself or in the door alignment. A worn deadbolt usually feels rough, loose, or inconsistent even with the door open. A door alignment problem usually works fine open but binds when closed.
- Measure the backset from the door edge to the center of the deadbolt hole, and note the door thickness so you can match the replacement.
If it works: You know the deadbolt is the problem, and you have the basic measurements needed for a matching replacement.
If it doesn’t: If the bolt works smoothly with the door open but hits the strike when closed, adjust the strike or door alignment before replacing the deadbolt.
Stop if:- The door edge or frame is split, crushed, or badly rotted around the lock area.
- The lock is part of a connected alarm, access control, or other security system you are not prepared to disconnect and reconfigure.
Step 2: Set up the door and remove the old deadbolt
- Open the door so you cannot accidentally lock yourself out during the swap.
- Keep the deadbolt unlocked.
- Remove the screws on the inside half of the deadbolt.
- Pull the inside and outside lock halves apart and set them aside.
- Unscrew and remove the latch from the door edge.
- Remove the strike plate from the door frame if your new deadbolt includes a replacement strike.
If it works: The old deadbolt, latch, and strike are off the door and frame.
If it doesn’t: If the trim will not separate after the screws are out, check for hidden screws or gently wiggle the halves apart instead of prying hard on the door finish.
Stop if:- The old hardware was covering oversized holes, cracked wood, or a damaged door edge that will not hold the new screws securely.
Step 3: Compare the new deadbolt to the old one
- Lay the old and new parts side by side.
- Match the latch length or adjustable backset setting to your door.
- Check that the bolt direction is correct so the beveled or marked side, if present, is oriented as the instructions on the latch indicate.
- Dry-fit the new latch and faceplate at the door edge to make sure the recess is close enough in size and shape.
- Confirm the tailpiece and mounting holes line up with the door bore.
If it works: The new deadbolt matches the door and is ready to install without forcing parts into place.
If it doesn’t: If the faceplate shape is slightly different, carefully square or widen the recess with a chisel so the plate sits flat.
Stop if:- The new deadbolt does not match the door bore size, backset range, or door thickness.
- The replacement requires major door modification beyond light recess cleanup.
Step 4: Install the new latch and lock body
- Slide the new latch into the door edge and fasten it with the provided screws.
- Insert the exterior half of the deadbolt through the door from the outside, making sure the tailpiece passes through the latch correctly.
- Position the interior half on the inside of the door and start the mounting screws by hand.
- Tighten the screws evenly until the lock is snug and straight. Do not overtighten and crush the door skin or bind the mechanism.
- Turn the thumbturn and key with the door still open to make sure the bolt extends and retracts fully.
If it works: The new deadbolt is mounted straight, feels solid, and moves smoothly with the door open.
If it doesn’t: If the thumbturn feels stiff, loosen the mounting screws slightly and re-center the lock halves before tightening again.
Stop if:- The bolt will not fully extend or retract with the door open after re-centering the lock.
- The screws spin without tightening because the door material is stripped or damaged.
Step 5: Install or align the strike plate
- Hold the new strike plate at the frame and check whether it matches the existing mortise and screw holes.
- Install the new strike plate if it fits, or reuse the old one if it is in good shape and lines up better with the bolt.
- Close the door slowly and extend the bolt to see whether it enters the strike opening cleanly.
- If needed, loosen the strike screws and shift the plate slightly for better alignment.
- Tighten the strike screws firmly once the bolt enters without rubbing.
If it works: The bolt lines up with the strike and enters the opening without scraping hard on the frame.
If it doesn’t: If the bolt is close but still rubs, mark the contact point and make a small alignment adjustment before testing again.
Stop if:- The frame is out of position, split, or too damaged to hold the strike securely.
Step 6: Test the repair in real use
- Lock and unlock the deadbolt several times with the door open.
- Close the door and repeat the test from both sides using the thumbturn and key.
- Check that the inside trim stays tight, the key inserts smoothly, and the bolt throws fully without shoulder pressure on the door.
- Recheck the mounting and strike screws after a few cycles and snug them if needed.
If it works: The deadbolt locks and unlocks smoothly with the door open and closed, and the repair holds during normal use.
If it doesn’t: If the lock still binds only when the door is closed, the remaining issue is door or frame alignment rather than the new deadbolt.
Stop if:- The key sticks badly, the bolt jams, or the door cannot be unlocked reliably after installation.
Replacement Parts
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FAQ
Do I need to replace the strike plate too?
Usually yes if the new deadbolt includes one and it fits the frame well. The new strike is designed to match the new bolt. If the old strike lines up better and is still solid, you can sometimes keep it.
How do I know what size deadbolt to buy?
Measure the backset from the door edge to the center of the lock hole, check the door thickness, and compare the bore spacing and latch style to the old lock. Matching those basics prevents most fit problems.
Why does the new deadbolt work with the door open but not closed?
That usually points to alignment, not a bad new lock. The bolt is likely hitting the strike plate or frame opening instead of entering cleanly.
Can I replace just the key cylinder instead of the whole deadbolt?
Sometimes, but whole deadbolt replacement is usually simpler for a homeowner and avoids compatibility issues between old and new parts.
Should I use a drill or a hand screwdriver?
Either works. A hand screwdriver gives you better feel and helps avoid overtightening. A drill is fine on a low clutch setting for stubborn screws.