I’m having problems with my old pickup and wanted to see if anyone help me out . I have a 1989 chevy 3/4 ton with a 350 and 3 speed auto . about a month ago it started not wanting to go into drive it will go thru 1st and second but doesn’t want to shift up to 3 eventually it would after it got warm or i drove a mile or 2 . No other problems reverse works fine as do 1st and 2nd no slipping nothing . As of this week it won’t go into 3rd no matter if I let it warm up or drive it . I’m wondering if there is a solenoid on these trannys that would be causing this or is the tranny on its way out the door ? Thanks guys .