Here’s another new 3D gadget for you. It pulls the wheels and gear apart.
Here’s the file for printing: https://www.thingiverse.com/thing:3417826
The linked file has a larger wheel cutout, sized for the SD70, which I believe is the largest diameter wheel. The cutout for the gear is sized for the larger 2-axle gears.
The jig requires three #10 screws and nuts. I found with fine thread screws, I could turn them by hand, even with gears that hadn’t yet cracked.