shift lever action

...The Answers are, Yes! and Yes! I think The spring is in that little cone on the right rear of the ZF. I'll check the ZF book and get back to You...

...The ZF Book shows TWO springs that return the 'Gear Selector Shaft' back to Neutral/Center. It APPEARS there is One Spring for EACH direction. One is Under the previously mentioned 'Cone', You'll need Snap Ring Pliers to remove it! The Other Spring is UNDER the 'Square' Shifter Box on the Drivers' Side Rear of the ZF; You Have to diassemble the parts inside(Ball Crank, etc.), and then remove the Box itself to access This spring (or so it looks in the cut-away view). NO gaurantees that You will be able to get everything Back where it came from after removing them!!! Have You checked the two setscrews locking the Ballcrank onto it's shaft? Get Yourself one of these ZF books with the exploded views and detailed instructions. And Call loyd Butfoy and see if He'll give You any advice...

I had a similar problem on my 72. Turns out, the big trim panel behind the seats would press down on the rear part of the console making it just slightly touch the shifter shaft. After some slight cutting of the trim panel where it meets the console and a small block of wood cut to the right thickness inserted under the rear of the console, all is good. Try pushing down on the back part of the console to see if that changes the shifter operation.