How to determine if assembly also needs replacement?

Question

How can you tell if you just need a new thumb latch or if you need to also replace the assembly?

Tom · Accepted Answer

Hello,

Basically, you'll need to remove the thumb latch and try to throw the internal mortise manually. You can do this with a screwdriver or something similar. If it works fine, then the latch is probably broken. If it doesn't work, then the mortise is what's broken.

Let us know if you have any more questions. Thank you!