Ha, I wish! only had a 3 yr /36000 mile warranty.... I'm at 3.5 and 57,000 miles.

 

I remember this one, it sounds like recall K17, it's a safety recall since it affects the blend doors for the defrost. Mine was done 2x, no charge, first time was just a recall notice but second time, air only came out the floor vent when it totally went out but still clicked for a while when turned truck off. First time was just an actuator test and reprogram of the HVAC computer. About a year later, had same noise as you describe, another reprogram and this time replaced one actuator. They had to remove the console to get the dash bezel off to get to the actuator. There are a few detailed posts on this here.