I can’t comment on the damage in bob-d motor, but I will say that there are a couple of big cavities in the typical OMC lower unit that drain through rather small and easily plugged holes. I have had to literally drill out compacted crud from these cavities in order to ensure free passage. Inspect the outside of the lower down near the gear case, look for any small ( 1/8″ ) holes, free communication to these holes from internal cavities is critical in preventing freeze damage.
Joe B
