We have encountered this many times on older model R62_72, and when we see one of those concaves we automatically add reinforcement. First time I've heard of it on the smaller model, though the manufacture is the same. Several years ago, Gleaner was providing an extra concave to custom harvesters so they could carry it along in case this happened to them. The welds holding the rear crossbar to the ventral ribs were very small due to the taper at the end of the rib, and weren't able to take the constant vibration of threshing operation, especially in viny beans or high moisture corn. When the rear crossbar would come loose it would be carried thru the cage by the action of the cylinder and would sometimes do considerable damage, especially to the helicals. Also, the P3 cage, due to the wider spacing as opposed to the P1 cage, will push out or dent somewhat more easily. This also will badly chip chrome plating both on the cage surface and sometimes a goodly number of the rotor bars, as well.
