I think your max towing capacity for your rv is only 5000 lbs....your 2500 Sub will be over that amount easily.
As far as the Sub is concerned, if the 4x4 transfer case has a neutral position, it should be towable.
I don't think this combination would be a good idea.
Ron, Sandie, and Maggie May
2013 Tiffin Phaeton 42LH
2011 GMC Terrain SLT-2