I recently installed a new Shimano 105 FC-5603 (triple crank). After about 300 miles I started hearing a faint "click" when my left crank arm was at 12 and 6 o'clock. Having troubleshooted square taper cranks for a few years, I figured something was loose on the spindle/crank arm connection.
The fore and aft 5mm pinch bolts were slightly loose. So I was more careful to make small, even incremental turns this time. That got me another 120 miles, and I'm starting to hear the "click" again. When I got to work today, I tested with my mutli-tool 5mm wrench, and the pinch bolts did not seem loose at all.
I was extremely careful to grease and really tighten the BB cups, so I'm confident my issue is specific to the crank arms. I've also followed online docs:
Anything else I'm missing? should I use loctite or use more/less grease in certain areas?