Worked on a Shifting problem today. Changed out the shift angle sensor. I pulled way too much plastic off, but then I thought I knew what was doing. Sensor is NOT on the Front of the Crankcase cover like a lot of others. On this Rancher it’s on the Rear Crankcase cover. If I had jacked up the back end and pulled the plastic skid plate off the middle section, I would have found it. It’s just a little off center on the left. 2 cap screws needing a 4mm allen wrench and pulling the gray connector off. 3 wires to this. Others have mentioned that the new sensor needs to be "pre-loaded" to fit onto the offset "key". Remove the old one and match the new one. That’s what I did and it worked well for me.
I also went to the front Crankcase cover and about dead center is the shift motor. 5 screws, 3 that hold the motor and 2 shorter ones on the bottom of the "gear case" All 5 must be removed. I found very little grease in there but I did remove it and put some Lithium Grease on the gears. I had read that the grease get hard when its cold and is another cause of weird shift problems.
Tested this out and all is good. If I had to change the Shift Angle Sensor out again, it would on take about 30 minutes.

Hope this helps someone else, it was fun playing with this and did fix the problem for me…