The only real solution short term is limit the torque of the 225 to protect the gearbox
People often say this when there is a problem with a gearbox - reduce its load and it will be OK, however in this case, since the failure occurs between the bevel gear and the oil pumps, I am not sure how reducing torque would affect anything, since the torque on the bit of the shaft that is failing would remain the same (just driving the oil pumps). I suppose there could be some reduction in bending caused by less torque, but I think you would need to be a transmission expert to understand if this were the case (which I am not!).