Tech Tip: Interlock Probe
Over a period of years, especially if the mounting bolt has been running loose, the probe can begin to bind if bolt is tightened completely. To correct this, add a #10 s. a. e. flat washer on each side of the spacer. This will give new meat for the spacer to tighten against and will decreases surface tension for the bronze bushing.
Note: This is also handy to convert the old style X-washer pin to the bolt and spacer. Just add a long link bushing to each side to bushing up and a washer on each side.