Teeth exhibit indirect valley cracks which are inaccessible.
They are under the elastic nylon overlay and run the entire length of the belt. Low tension operation allows the
teeth to rise out of pulley and a rolling effect is created. The adhesion of the nylon overlay becomes unbonded
and a crack appears. Crack development will extend into the teeth and fabric will break to produce an open crack.
ACTION:
Ensure tension is to OEM specification on a cold engine
and repeat procedure during belt "settle-in" period.
TEETH VALEY CRACKS (DIRECT)
FEATURES:
Affectionately known as "whale mouths". Teeth exhibit
direct open cracks which are normally present on entire length of the belt. Cracks may be more apparent on one
side of the belt or equally be of the same severity across belt width. Low tension operation allows the teeth to
climb the pulley and an imposed rolling effect of the teeth occurs whereby fatigue cracks are initiated. Natural
crack progression to the point of teeth strip will quickly result.
CAUSES:
GENERAL:
Affectionately known as "whale mouths". Teeth exhibit
direct open cracks which are normally present on entire length of the belt. Cracks may be more apparent on one
side of the belt or equally be of the same severity across belt width. Low tension operation allows the teeth to
climb the pulley and an imposed rolling effect of the teeth occurs whereby fatigue cracks are initiated. Natural
crack progression to the point of teeth strip will quickly result.
ACTION:
Ensure tension is to OEM specification on a cold engine
and repeat procedure during belt "settle-in" period.
