Beginner at drivers, help please.

Hey guys, I’m having a little trouble with my project.
I’m in college and neither I nor my lecturer can find a solution to this.

I have made a basic cartoon tank and I have rigged the tracks to the body etc. I am now focussing on the tracks ‘rotating’ when the tank is moved.
I have set up the driver for the y-axis and it is working perfectly fine.
I have used the same method for the x-axis as I did with the y-axis. Although, the tracks are rotating in the wrong direction and I’ve tried absolutely every method I can think of/find to fix it, but they still won’t rotate in the direction I want. I have uploaded my .blend file for you guys to have a look at, any help would be much appreciated.
Thank you.

The track I am focussing on first is trackLand it is parented to boneLwhich is parented to Empty, which I use as the main body to move the tank.
As you will see, if you select the Empty and move it along the y-axis, the tracks will both rotate in said direction. (forward, they move forward and vice versa).


blueTank-BEDIT.blend (792 KB)