440 crawler stress cracks

[carolina crawler]

HI fellow crawlers....does anyone know if the old 440 crawlers are known for developing stress cracks in areas above the finals,closer to the front but not in the frame.I wana say these are supports, or the upper part of the unit. after cleaning some crud off my crawler I noticed cracks in the metal...My crawler used to have a back hoe, and I can only think that these were caused by it,overloading?...not sure...I am going to post some photos to show the areas.....and the seat on my unit has some strange looking pivots on the sides, almost looks like a smaller version of the large mounting area on a 831 loader...these brackets are moving pivots of some sort.........thanks for any info....Mark/CC