That works, thanks!
It looks like you need a larger gear reduction than what you have right now. If you can put a gearbox between the CIM and the climbing shaft, then the climbing shaft will have more torque. This would probably work:
http://www.andymark.com/ToughBox-p/am-toughbox.htm
I am not sure how long shipping takes to your part of the world. Do you have any other gearboxes, or know teams in your area that might have old gearboxes?