MIWA B5 security thumbturn operation repair of defects

"thumbturn movement is bad"

It was a medium-sized property that was built 16 years ago. The entrance door was a PR cylinder double lock. There is a security thumbturn which is rare in apartments.

The thumbturn movement was certainly a bit of a drag. It seems that it is difficult for the client to operate by pressing the switch button to lock and unlock.

When I took it apart, it was pretty dirty inside. Remove dirt with special cleaning oil. Somehow the operation improved smoothly.

It is a rare symptom that thumbturn causes such a defect. It was quite scratched, so I wonder if it was possible to install second-hand parts.