2015 KOP gear box binds up

[DonRotolo]

I don't have a 2015 trans to look at, but in past years gears had a small shoulder on one side, at the hub. If assembles upside down (inside out?) it would cause binding.

The shoulder looks like a ring-shaped bump surrounding the hole in the gear, on one side of the gear only. It is not very tall and easily overlooked.

[dradel]

we had this issue as well. this is what i found today. At first I thought the output shaft was contacting the input gear, so i put it in the lathe and spun a little off. NO change

I had just the input gear in the housing, and was spinning and noticed the gear was wobbling??? So i then put the short shaft that the lathe and spun it to see if it was true.... Straight as an arrow. I the put the input gear on it and wobble came back. Long and short of it is in our case the input gear is out of round. Had another from an extra tough box mini so checked it and put it all together and all is well