93 nissan quest tranny

Hi I have a 93 nissan quest minin van, 3.0 gxe, with 167000 the tranny for the last few months has taken a long time to shift from 1 to 2 gear, and when shifting into over drive its shuttered or cluncked. Now it doesn't have reverce or 1 gear and nertaul acts like drive. I would appreciate any comments. I did have the fuild changed at about 120000 miles. it was at a quick lub place, where they pump out the old and pump in the new. I've also priced used trannys just incase, about 450 dollars. I've changed a dozen or more rear wheeel drive trannies, and a few motors too. I'm not afraid to tackle this but any hints would be good too.

OK i have the same problem with my 93...Hopefully sombody will
reply with a fix.....So far it seems like it might be a control unit
either in the tranz or next to the main computer in the van....hopfully
ill get to know more about it monday.If I finde my problem ill post back.