From what i've heard you can pull the elec motor from the TC and it'll run 2wd for dyno-ing (dont know how that works really) but i've also heard sometimes things get burnt up....cant remember if its the trans or something else though.
I pulled my front driveshaft once hoping for 2wd and all it did was spin the front TC output, heck in park it even rolled out of the garage when i leaned on it