Just discovered a crack yesterday on my 1A.
Exactly the same location as yours bro.
Am really sad. Such a beautiful toy but this
spoils everything. Was planning on getting
a CF, but this incident is preventing me.
If they only made that portion lock on the
back of the chest, that portion won't be
too stressed. Yes, articulation will suffer
but that's better than having cracks.
The tightness of the ball joint at the shoulder
further aggravates the problem.
Yamato should consider hiring a a stress engineer!
These cracks are not QC related. They are due to faulty
engineering.