Column Shift is extremely hard to shift past Drive

[MugzAngel]

This is my first post (Question), I have an 1987 Chevy R10, it is automatic 350 tbi, transmission is 700R4.  The trucks been parked for about 4 years, under a patio, we got the truck going, runs real good, passed smog (California), but when I try to shift past the OD, it feels like that's as far as i can shift, even though I still have Drive, 2, and 1st to get too..  Could something have rusted? that prevents the shift column to shift normally?

Thank you in advance

[Irish_Alley]

you could disconnect the linkage at the trans its only a clip or pin not sure. but then try to shift it see what it does.

[MugzAngel]

That sounds like a good idea.  I will try and report back, once it is done.  Thank you