[Starboard M]

My house has several old door knobs that are loose that I would like to tighten up a bit.

Quick google search seems to point me to they are Mortise locks. However, everything is showing how to repair internals of the mechanism.


The knobs fit onto a square "stud" which then goes through the door. The knobs fit but allow about 1/4-3/8" movement in and out. There are adjustment holes, but the next one in are all to small.
Clear as mud?

Pictures, although they might not help much.

The knobs do not have a spacer or anything that sit between them and the door itself. It just rides on the metal portion.




My question is, how do I get these knobs to be tight again. Last thing I want to do is replace them, but they are annoying.

House was built in 1923 and is located in Denver if that helps. Seems to be the original doors and knobs.

Thanks!

 

[funfool]

May not be able to.
The set screw on the knobs, if you loosen them up you can unscrew them from the shaft and unscrew the knobs to remove.
Sure you know this already.

You may be able to loosen the set screw on one knob and loosen it a 1/4 turn.
Then take the other side and tighten it 3/4 turn to achieve what you want ... play with it and try to find middle ground.
It may be the threads are stripped at that point and will not tighten.
Maybe unscrew one side a couple turns to get to unused threads and then tighten other side down.
Just need to play with it, pull the knobs off and inspect the threads, see what shape they are in.
Could also be the threads inside the knob itself.

May be able to look on line and find replacement parts for them ... but they are old and will have wear on them.

 

[spotco2]

The knobs screw onto a square spindle and lock in place with a set screw at the base of the knob. This means there is very little chance that you will ever be able to screw in or out to the correct position without some handywork. Screw them in to far and they do not turn freely. Back them off 1/4 turn and they flop around.

We have repaired this in the past by using different sizes of spacers between the knob and the plate on the door. We have used plastic plumbing washers and even rubber o-rings with good luck.

 

[Maintenance 6]

The square "stud" is called a spindle. There are two basic types. One type is threaded and the knobs screw onto it and are then locked in place by a set screw. The other type has sets of threaded holes. The knobs slide onto the spindle and a screw then attaches the knob to the spindle. On the threaded type, you adjust the knobs in and out and then lock them when they are in the appropriate position. The spindle with holes requires that you use washers to shim behind the knob and eliminate the end play when you reach the closest screwhole. You need to lubricate all of this and be sure that the knob return springs are working inside of the mortise case.