The tractor has a frame that the front loader is attached to, and the frame is bolted to the bottom of the engine block. We have lost two front drive shafts as a result of the bolts viberating out. We have had to drill and tap the bolt holes, in which makes them larger and that much closer to the inside wall of the motor. We have had to purchase drill bits, tap bits, bolts; lock washers, tread locker, 2 drive shafts, and collars that hold the drive shaft on. please help us resolve this issue. the dates i dont know this is the third time its happened.