'96 Nissan Quest 3.0L mini-van

This vehicle has over 200

Vehicle not shifting well, added Lucas treatment. Is there a filter within the tranny I can access easily or a sensor I should replace? I haven’t found a repair manual for this vehicle or any info about it on AutoZone’s online repair guide. The wife is after me to fix it, we can’t afford a mechanic. H-E-L-P !