Sliding Door Lock Replacement: What to Buy and How It Goes In

Replacing a sliding door lock (on an Arcadia door, as Arizonans call them) usually means swapping the handle set and the mortise latch inside the door edge. The hard part is buying the right size: measure the screw-hole spacing on the handle and the latch body before you shop, or take the old parts with you.

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Is replacement the right fix?

Before you buy parts, make sure the problem isn’t line-up. If the hook swings fine but misses the keeper, a roller or keeper adjustment is the fix. See sliding glass door won’t lock. Replace when:

• The hook won’t swing out or is loose
• The handle is cracked or the lever spins
• You want a keyed lock from the outside
• The latch is rusted or bent

Measure before you buy

1. Handle screw spacing. Measure center to center between the screws that hold the handles together.
2. Latch body size. Remove the latch from the door edge and measure its height and the screw spacing on its faceplate.
3. Door thickness. Handle sets fit a range of door thicknesses.
4. Latch style. Note the hook shape and whether the lever is vertical or horizontal.

Many sliding doors use different hardware. Taking the old handle and latch to the store, or matching by brand and model if they are marked, is the easiest way to get the right part.

Swap it step by step

1. Unlock and open the door partway.
2. Remove the screws holding the inside and outside handles together.
3. Unscrew the latch from the door edge and slide it out. Note how the lever connects to it.
4. Fit the new latch with the hook facing the same way as the old one.
5. Attach the handles, making sure the lever engages the latch.
6. Test with the door open: the hook should swing out and back smoothly.
7. Close the door and check that the hook catches the keeper. Adjust the keeper if needed.

Keyed from the outside

Some handle sets include a key cylinder so you can lock the door from outside. If yours has one, the cylinder is often removable or replaceable. Bill’s video above shows how a lock cylinder comes out. Whether a sliding door cylinder can be matched to your house key depends on the brand. Check with the handle maker or a sliding door specialist.

Don’t forget the extras

A new latch is only part of a secure sliding door. Add a security bar or pin lock so the door can’t slide even if the latch is defeated. See sliding door security bars and extra locks.