Is there a way to turn off the sh-awd system without damaging the rear differential/transfer case parts

 

Limp mode or disconnect the drive shaft are the only ways I know of disconnecting the sh-awd system. Not 100% sure you still won't damage the sh-awd rear diff if you are towing on all fours with drive shaft disconnected? Do you want to disable for towing behind a vehicle?

 

I would like to just see how it handles whilst only the front wheels are powered

 

Here are some words of wisdom from the best Honda/Acura tuner around (Derek Robinson with IMW) regarding steps to dyno the RDX on a 2wd dyno. You may be able to use these steps to drive with FWD, but I'd be weary as no one is sure if it could cause damage over time.

 

Unplug one of your wheel speed sensors.