Stress plot for shaft with torsional load

SW Sim Folks,

Attached is a picture of a simple shaft with a pin inserted through a cross hole. The shaft is green with a split face on the left end that is highlighted in blue. A torsional load is applied to the right end of the shaft. The blue highlighted face on the left end is inserted into a housing (not shown) with a slip fit. The red cross pin fits into a hole in the housing to prevent rotation (and also translation) of the green shaft. The actual components I am studying are much more complicated in terms of geometry, but the basic principle is the same. We had a failure of a shaft at the cross pin hole. My intent is to get a study setup that we can use to compare alternate materials as well as design changes if necessary, not only for the cross pin hole but also other stress concentrated areas in the shaft geometry. I am having difficulty determining the correct stress plot to use for this situation and how to properly set it up. I think I need to plot shear stress rather than Von Mises because it's a purely torsional load with virtually no bending.  I am uncertain as to whether I need to plot TXY, TXZ, or TYZ. I've read the help about shear stress plot but my understanding is still cloudy. Also, is it helpful/necessary to create a coordinate system to be able to orient the plot in the correct direction to show max stress? I appreciate any help you guys can offer to clear up the confusion in my mind.

I've also attached an example study. Please take a look at it. I'm interested to hear your ideas and recommendations.

Thanks,

Aaron

SolidworksSimulation