i am getting a snaping sound when i back up or go forword, when i have it in 4X4 , it dont sound good, any idea what it could be , this is the tractor that they had to split in half to replace the pto shaft that was bent at 3 Hr , Now i have 31 Hr on it , any way, what can i look for or check , like i said it is a real bad snaping sound , not when i let the clutch out, but when i am moveing about 3 to 4 Ft each way ,then it snaps, Thanks Frank