I don't see a picture, but this may work with the following assumptions...

1) the case is plastic (nylon or another plastic)
2) the crack is not on a piece that is required to flex

Something I used to do with my old electric car parts was use cyanoacrylite (crazy glue, ZAP... etc.). The parts were nylon. If it's just the case and not any of the moving parts you may be able to do that. Use the gel (thicker stuff). Clean the surfaces very well. Any grease is going to prevent adhesion. Press and hold the pieces together and then sprinkle some baking soda over the glue that weeps out of the racks. This will harden it instantly (creates alot of heat as well). Then I'd blow off the excess baking soda and run another bead of glue over the crack. Don't be affraid of being liberal with the glue. I used to do this for a number of pieces when I was in a jam. Just remember that the joint will not flex very well.

All of this is with the assumption that the case is made of nylon or another plastic. I've even used this method to fix fairing clips on a friends motorbike.

Ahh now I see the picture.
I've used this methode to glue the nylon shock towers on my old electric and it went pretty strong for quite some time. If you're in a real jam and absolutely cant live without the car on your trip you might try it.