Ujoints ?

2006 F250 4 x 4 6.0 ,160,000. While driving, I suddenly hear a grumbling/roar coming from under the back of the truck. I realize it only happens on deceleration or coasting, not under a load.

The mechanic (has not inspected yet) thinks it may be U joints, as they typically last 150,000+/- miles.

My question is 1) Is the consensus U joints?

2) How many hours labor to replace all 3 plus the carrier bearing?

Thanks