By setting lever spring, do you mean the setting lever jumper? If so, that really isn't a part that I would suspect being the culprit for this problem.
Three things come to mind immediately when this problem arises generally:
1 - Stem is cut slightly too short.
2 - Damage to the pin on the setting lever that fits into the slot of the stem.
3 - Damage to the stem on the inner flange that makes up the side of the slot that the pin of the setting lever fits into.
Cheers, Al
Click to expand...