New 2010 Sierra 4wd Clicks during acceleration
 

Hello List
I am a new truck owner. Just purchased a new 2010 Sierra 4wd Crew Cab. And am loving it. However, after starting the engine, begin to drive, I can hear 2 click sounds at about 10mph. I can also feel the click thru the gas pedal. The service guy tells me there is a clicker valve (not sure what the exact name was). Is this a normal behavior from the truck?
Please ease my mind.
BrokeDownRunner

i have the same noise in my 2010 sierra 5.3 2wd.
and can feel it through the pedal

I have the same thing in my 2009 Silverado Crew Cab. The dealer tells me that it is normal. There is also a slight hesitation on slow acceleration associated with the clicking.

Noticed the same thing on my '10 silverado crew 4wd...