Some years ago Manitex came out with a turret mod after some failures in that area. All these failures were caused by severe overloading or so I was told by a long time Manitex New York City area fleet operator. He was not affiliated with the company so I tend to believe him as recounting the facts correctly. He said the crane can do so much operated correctly that some wanted it to do even more.
He freely told me this as I was inspecting my current machine, which I subsequently bought from him. I didn't ask about it as I didn't know. He went on to show me the mod, it is basically a big gusset that further ties in the horizontal turret to the vertical mount that ties into the mount frame. It was an overkill solution he said, as many were still operating without that mod, just not overloaded. Whatever.... mine had the mod,and I'm still very happy with my purchase.
A few years later, a buddy in Arizona bought a 22101S, based on my experience with what a great bang for the buck it represents in the light crane market. After three different behind the cab boom trucks, this sitting on your arse while having all the other benefits of the design, made me a believer to this day in the design. Anyway, his DID NOT have the mod, it had over 5000 hrs on it, and with no problems. Based on my telling of my story concerning the mod, he had the mod installed by a big time Phoenix area dealer, who claimed it was overkill and not needed. End of story....if you have a 22101S, don't overload it. Get the mod if it doesn't have it already, and THEN don't overload it, common sense really! If you have ANY type crane, don't overload it!