I have been looking at electric shifting problems on this forum. I have read the posts on ES problems, but I think the problem is internal. This machine has stripped a tooth or two off three new shift motors over about a two year period. One time also stripped teeth off outside of the shift reduction gear. Each of those times the machine was manually shifted into neutral and after a new shift motor was installed then the trans shifted fine. Now installed a new shift motor and it will only shift into first gear with the electric shift being pushed several times. Every time the button is pushed it sounds like it is shifting, but seems to jump back into neutral. Once it shifts into first gear then it will shift up and down until shifted back to neutral, Then the same problem hard to get into first gear, cold or warm does not matter. Seems like if you shift into reverse and then into first it is likely to shift into first gear easier. Checked the reduction shift gear, the angle sensor and the clutch adjustment all are good. This machine is a farm machine with moderate to hard use seven days a week. The machine has 5600 hours. I have come to the conclusion the problem is internal. Any ideas on what the problem is and how deep is the problem?