not shifting into OD

[MiniMe]

I am slowly bringing an 89 B2 2.9 Automatic back to life. The tranny wont shift into OD . Other than not shifting into OD it shifts good in all other gears.. Supposedly it shifted great b4 it sat for so many years. Im hoping its something simple. I dont want to sink any more money into this thing until I get the shifting problem fixed. Where should I look first?

 

[The Fonz]

The OD is apparently the week point of the A4LD, I had the same woes coming home from classes one day. My trans kicked out of OD when I accidently hit the hazard switch and wouldn't go back in. Strangely enough I changed out the turn signal switch. No problems since.
But the OD is a gear that gets extra wear so it could well be a mechanical issue as well.