Hi Pauz21, D-Gottlieb, currieddog, HowardR +
"shortening a retaining spring" (or tightening an retaining spring wound around the axis on a stepper) or other treatment: Seldom - but once in a while a spring needs some work. I remember a weird situation on "Gottlieb Hot Shot" --- Test-Lights mounted, videos made - looooong topic - and in the end: https://pinside.com/pinball/forum/topic/the-many-problems-with-my-gottlieb-hot-shot/page/2#post-4122570 --- see the picture "spring" --- and the picture in post-68 (spring) --- seldom, rare: Sometimes we have to work on a spring. Greetings Rolf