Well took the tires off the trailer to drop them off to replace the cracked valve stems. Dropped them off and about an hour later the service manager calls me and says they are done but when their mech. was working on them he found cracks in 2 of the 5 rims. Upon arrival he brings me in the shop and shows me the cracks which were located inside the area where the center cap rests. each of the cracks is adjacent to the hole where the lug nut rests.The rims are the Ultra Claw rims, The Mgr. told me he has seen similar cracks on utility trailers that were overloaded but never on a boat trailer. He said that if it was his boat he would not drive any distances until they were replaced This is the first time I have had the wheels off so I dont know what to do.