What's wrong with my Schlage L-series mortise?

[htroberts]

I have a Schlage mortise lock (it's an 9453, I think) where the inside knob 'slips' sometimes when you're trying to turn it. So you can turn the knob, but the deadlatch does not retract. The lock seems to operate correctly from the outside knob (assuming it's unlocked, of course).

I've replaced several of these mortise bodies, but I wonder if the problem with this one is in the body or in the knob and shaft that goes from the knob to the lock body.

Thanks,
Heath

[RedE]

So the regular latch bolt retracts fine but the auxiliary deadlatch does not?

I have a Schlage mortise lock (it's an 9453, I think) where the inside knob 'slips' sometimes when you're trying to turn it. So you can turn the knob, but the deadlatch does not retract. The lock seems to operate correctly from the outside knob (assuming it's unlocked, of course).

I've replaced several of these mortise bodies, but I wonder if the problem with this one is in the body or in the knob and shaft that goes from the knob to the lock body.

Thanks,
Heath

[jimu57]

Does the spindle engage the knob and also the lockcase?

[ltdbjd]

I've had them slip when the spindle was twisted, but it's pretty obvious looking at the lever. I'm not sure if the knob would look the same.

I've had similar issues when the hub retainer or hub spacer shifts. Typically you can tell this is the problem when you remove the spindle. The hub doesn't appear to be centered, or if you turn it with a screwdriver, you can feel it move around.

There are also parts that connect the hub to the deadbolt to retract it. These can break, however in my experience they rarely do. More often than not, one of them gets knocked out of wack.

Sounds like you might have to pull the cover and see what's going on.

[htroberts]

So the regular latch bolt retracts fine but the auxiliary deadlatch does not?

No.

The thumbturn operates the deadbolt reliably (100%). If the thumbturn is in the unlocked position, the exterior knob retracts the deadlatch and auxiliary deadlatch, together, reliably.

The interior knob retracts the deadlatches about 80% of the time. The knob will turn, but not spin freely--there's some tension from either a spring or friction, but it feels like it's slipping, and the latches don't retract. You can try again, and, so far, at least, it will eventually work.

[htroberts]

I've had them slip when the spindle was twisted, but it's pretty obvious looking at the lever. I'm not sure if the knob would look the same.

I've had similar issues when the hub retainer or hub spacer shifts. Typically you can tell this is the problem when you remove the spindle. The hub doesn't appear to be centered, or if you turn it with a screwdriver, you can feel it move around.

There are also parts that connect the hub to the deadbolt to retract it. These can break, however in my experience they rarely do. More often than not, one of them gets knocked out of wack.

Sounds like you might have to pull the cover and see what's going on.

Okay, thanks. If I'm understanding what you wrote, all of these causes are inside the lock case.

[cledry]

Pull the body out and see if the screws holding the case together have backed out. If so, take the case cover off, pop all the internals back where they belong and reinstall cover with blue Loctite. Make sure the screw that hands the spindle hub hasn't backed out. Make sure the mortise cylinder has the L cam and not the straight cam.

[RubberBanned]

Could this be a fatigued spring cage? I guess it wouldn't give the tell-tale sag without a lever, but it might be possible?

[ltdbjd]

I can't picture that causing the intermittent problem he's experiencing. The OP didn't post what he discovered, but I'm still thinking the hub is moving around on the affected side, or it's in one of the internal parts that shifted out of place.

[htroberts]

The OP didn't post what he discovered[...]

Sorry, guys, I've been meaning to close the loop and tell you what I found.

Playing around with it some more, I realized that if I push on the knob when it's not working, it starts to work. I realized the nut that holds the lever to the "inside lever mounting plate" was ever so slightly loose, and tightening that up made things better as well.

It was only after driving away that I was thinking to myself that depending on that nut being tightened exactly correctly is a really poor design, and looking at the diagram, I realize that's not how it's designed...

The problem lock is missing the spring on the spindle. Ordered a new spindle and it seems to be reliable now.

Page 44 here:
http://us.allegion.com/content/dam/alle ... 106500.pdf

[Squelchtone]

Glad you figured it out and a big thanks for taking the time to visit and share your update with us, always appreciated!

Have a good day!
Squelchtone

[billdeserthills]

The OP didn't post what he discovered[...]

Sorry, guys, I've been meaning to close the loop and tell you what I found.

Playing around with it some more, I realized that if I push on the knob when it's not working, it starts to work. I realized the nut that holds the lever to the "inside lever mounting plate" was ever so slightly loose, and tightening that up made things better as well.

It was only after driving away that I was thinking to myself that depending on that nut being tightened exactly correctly is a really poor design, and looking at the diagram, I realize that's not how it's designed...

The problem lock is missing the spring on the spindle. Ordered a new spindle and it seems to be reliable now.

Page 44 here:
http://us.allegion.com/content/dam/alle ... 106500.pdf

I keep the part # Z, lever spring cage in stock for use with sagging levers, I have actually
mortised them into place in wooden doors, under the trim-- they do a great job at holding a lever handle in place

Are you sure the spring cage isn't missing or worn out?