The 8 speed transmission on my 314-8, M/N 73400, S/N 5900282 just went. It sounded horrible as I mowing and going down a slight downgrade. I heard a loud clanking sound, the sound of metal on metal, and at the same time the tractor jerked violently with sudden forward movement, like 1st gear was going in and out of engagement. I immediately stopped the tractor, placed it into neutral and disengaged the PTO. Then no matter what gear, 1st or 2nd or Reverse, the tractor would jerk violently with the clanking sound after I disengaged the clutch. I pushed the tractor in Neutral back home. Now without the tractor running, the tractor free roles, like it is in Neutral for all gears, 1st, 2nd, 3rd or R. When I try to place the tractor into gear with the engine running while releasing the clutch pedal the tractor will start to die. Do I have a blown transmission? How do I determine if I have a 5086 - 4 pinion, 5073 - 10 pinion, or 5091 - 8 pinion? Is this a fix that I could do myself or am I better of doing a swap for a used transmission? any help would be greatly appreciated. Thanks.