MAZDA B4000 DRIVETRAIN

What Could Be Wrong If I Have An Au­to­matic And It Is­n't Switch­ing Gears It Tacks Out In Sec­ond And Re­verse Goes In And Out

I Just Changed The Trans­mis­sion Fluid (the Rec­om­mended 3 Quarts), Fil­ter, And Gas­ket In My Truck, And Now It Won't Go Into Gear. The...

When Shift­ing From Park Into Drive Or Re­verse There Is A Hes­i­ta­tion And A Shut­ter (all Though Very Slight) Is Felt And When Mov­ing For­ward...

I Have A 94 Mazda B4000 4l 4x4, It Was Run­ning Fine Un­til Last Night When I Was Dri­ving Along And It Droped A Gear, Hard, And Did­n't Want...

I Can Shift From Park To Any Gear, But Not Back Up, I.E, Into Drive But Not Back Up To Any Gear. I Can Get Un­der Truck And Put Back Up...