3 Speed Jumping Outta Second Gear?

[SayBye]

Just got my truck out and "drove" it for the first time since buying it and its popping out of second gear. Goes into second fine, no grinds or anything. I can hold the shifter in place with my hand and it will stay in second. Where should I start?

I really don't know much about how the three on the tree works, can somebody link me to a page that has a column tear down or rebuild? I searched but didn't come up with much.

Hoping this is something in the linkage or something simple and wont have to get into the transmission. Its interesting that its just second gear since it sits in the highest position and gravity is working against the shifter... (fingers crossed)