shifter knob

Has anyone tried to repair (not replace) the shift knob trigger for an automatic transmission? The repair kit includes the trigger, spring and the part that the trigger pushes. Can it be installed without removing the knob?

I've been having this issue for a few months now, and need to address it as it's getting annoying. When I park the car and hit the ignition off button (2012 Regal GS auto), more times than not, the driver information centre shows the SHIFT TO PARK! message. The engine will shut off, but the...