i have had two pans crack on gleaners one on a big engine l and another on N6 according to my dealer in north idaho the have seen several over the years, they think cause of the vebration out of the output shaft. never a problem on the tractors. I brazed both of mine, drill out the cracks with a small drill bit and go for it, total cost of repair just basically some rod and a pan gasket which cost me 7.50 for the N6 we did this fall.