After 2 years of good use, left crank arm on my FC M542 crank set has started to get loose quite often (cca 500 km). It is usually indicated first by few now an then clik-clanks somewhere in the region around BB. When checked, bolts are loose, and safety plate looses it's "nose"
As far as I can see there are 2 visible problems:
- the spline on the crank arm shows some wear, but they do not seem completely damaged.
- one of the fixing bolts is not original Shimano one M6x19, but M6x20 from hardware store with filed head so that it can be inserted in crank arm. It is also missing washer.
I intend to buy original bolt with washer. Other than that, is there something I can do to delay changing the whole crank set?
Maybe using some threadlocker like loctite 242? Where would I apply it on the bolts or on the spline? If it is applied to the bolts, does that mean that I have to use more force while tightening them, or just use force as usual?