Odd one if as you say was correctly torqued & no crashes.
I guess the guard sits correctly. Your not fighting any springiness in the metal?
There could be 'fatigue' stresses from the engine vibration.
Is that an M8 screw?
Even the lowest tensile bolt should be good for >2 Tonnes basic shear strength. Even a crash shouldn't shear it.
??
A high tensile bolt would fare better but hopefully its's just a one-off duff bolt and it never happens again.
(Is my thoughts)
-A
I guess the guard sits correctly. Your not fighting any springiness in the metal?
There could be 'fatigue' stresses from the engine vibration.
Is that an M8 screw?
Even the lowest tensile bolt should be good for >2 Tonnes basic shear strength. Even a crash shouldn't shear it.
??
A high tensile bolt would fare better but hopefully its's just a one-off duff bolt and it never happens again.
(Is my thoughts)
-A