I personally make the TSB many times. becose i am ... a tech from kia. and , sometimes, the crankbolt can broke even if the TSB was done. It appen 2 times at my garage. the best way to know if the TSB was done is the color of the bolt : the original one was metal color without coating and the new one was silver coating and it should not have any lock-tite of any color or any grease on the tread. if you cant have any help from KIA and you have to pay for it . DONT replace the crankshaft in first. try to find a good machinist and he can drill into the crankshaft to put a new bolt . and yes the belt should not be to much tight. a cranck shaft job complete can cost as much 1000$ can and a drill out cost around 350$ can if the radiator and the front was removed .