the balanced portion of extewrnal balance on these units is not in the outer ring, it can come looser, fall completely off and it wont cause a broken crankshaft, no way no how. the balance portion of it is in the center part of the hub, and that cant move. the outer portion only takes out the harmonics vibraions of the crankshaft. sure you shboulod take a look at your balancer, if he rubber is getting rotted or the balancer wobbles at all, repalce it, bujt it alone wont cause an engine to break its crank. now the cast iron crank will break on its own, just because its a crap made product. adn if it was EVER rebuilt and turned by somone that didnt know crap aout them and didnt turn the proper radius in the shoulders of the crank then modify your bearings to fit, sure its gonna break, but ther are litterally thousands of these out there on the road working great with hundreds of thousandds of miles behind them, just drive it slow like its suppose to be,,,if you want a hot rod diesel,,,,put a detrot in it!