Bit of info: Some CAT308E CR excavators may have cracks in the boom around the stick cylinder rear mounts on top of the boom, check with your CAT dealer, they carried out a crack test on four of the 308E excavators for a company I contract to and all four had cracks, clean off the paint along the welds length ways and across the boom then use a crack test spray, it may be covered by CAT warranty.
Do you have any photos showing the cracks..? It seems this issue applies to 308E & 308E2 CR machines of S/N prefixes GBJ, FJX, & TMX. There is a repair procedure available and also it appears there is some sort of factory support although I have no specific details on exactly what form that support takes. From what I can see Cat dealers should be contacting the owners of all affected machines to schedule an inspection of the boom by a dealer tech.
Sorry I don't have any photos. The reason I brought it up was these machines we have are used by pipe crews laying pipes, and there is a possibility of it snapping while lifting pipes etc. with guys in close proximity.
Mine was recalled and repaired by my Cat dealer at no charge prior to cracking. It is a TMX prefix.