I have an '83 T/A with a 700r-4 trans and a T-handle shifter. The problem is that the plastic piece (dowel rod thingamajigger) that is in the stem of the shifter seems to have broken and fallen in deeper than it should be.

Usually the thumb trigger would push it in to bypass the reverse lockout. I can get the car through reverse and into drive from park and vice versa. When the trans is colder, it sticks a little. Obviously this needs to be fixed. What steps should I take to repair this? What exactly needs to be done? Anyone know?

Thanks in advance!