Cracks in body near King Pin

Thanks for the info....the only thing I find odd is when we put it into storage last fall, all was fine. We drop it off in a lot and the storage owner uses a tractor to move it to the storage lot. Then when we need it, he pulls it out. We noticed the cracks when we got it out this spring. Now I have no way of knowing if he accidently hit the underside when hooking up. The lube plate was also cracked/broken also(gives me more reason to think of operator accident). Of course, the lot owner won't confess to anything....he maintains that the very cold winter here in MN caused the cracking...sounds like "B" as in "B", "S" as in "S" to me.....