Hello to all who wrote in. I was able to repair the problem with your help. It seems the 2 ears Don mentioned were loose and had drifted out of place allowing the shift lever to be displaced. It appears this had happened before since the ears were being kept in place using a wire tie. When this got slippery w/gear lube it moved and the ears moved allowing the shifter to move around too much which broke the pin keeping the lever in place. The lever had fallen to the bottom of the tranny which meant I had to open the inspection plate to get it back (and allow me to remove the broken pin). I have since replaced the pin and am using a hose clamp to keep the ears in place. Easy peasy!

Thanks to all who wrote in! It is an easy truck to work on but it's nice to have help out there.

Daniel