Low growling/groaning from driveline

[Beltbuckle Bill]

Here's one for you guys. I'm having a hard time diagnosing this sound and am really hoping someone can help. I have a 2010 Sierra 1500 with 4.8 and 4L60E, 2wd.

I've never heard a sound like this come from a vehicle before. It sounds like a massive old wooden door groaning. Not a squeak but a low guttural groan.

Here are the symptoms
-groan when accelerating hard off a stop, through 1st and a little into 2nd
-If I'm light on the throttle taking off it makes no sound
-truck in drive, foot on brake, it will groan when given gas
-no noise in reverse
-no noise at speed
-different rpm does not change the sound it makes
-might be worth noting I have what I think is excessive driveshaft rotational play when parked. Like it can be rocked back and forth too much. U joints appear good

Something is not happy when the powertrain/driveline is torquing up

[asilverblazer]

Grease the u joints and clean up the driveshaft yoke going in to the transmission.

 

Carrier bearing present? Condition?