Drive Shaft Click

Why the dickens would you drive it after that happened?

Sounds like U-joint. Also check front driveline shaft on 4x4, sympathetic motion can sometimes turn shaft when not in 4x4 mode.

With play in U-joint, joint slips to one side as Torque pushes against flange to turn driveshaft. Basically U-joint is cocked and shaft is not running true to center plane.

Also worth checking are front c-v joints if 4x4 vehicle. Pretty much the same problem can exist with these small joints as with the big joints on your driveshaft.

The last areas are the motor mounts and transmission mounts. These can cause the same problems you describe. And remember that sound transmits differently through metal.

I would check the rear drive shaft slip joint and u-joints for failure as this is just at the rear of the box.

Front axle shafts or drive shaft, are the ball joint all nice and tight?

Sounds like it needs a major repair in the rear differential or else the rear U-joint is near failure.

sounds like u are having front drive line problems. the press button 4x4s are not a good idea to have. transfer cases go out very easily. so check front drive line.

Is it full time four wheel drive? could ot be stick in 4X4 as this will make nasty noises unless dead straight.

the seal might be bad

Check transmissio fluid?

Start by checking the axle half shaft u joints and then the drive line u joints for worn or loose end caps. Also if you have a constant velocity joint on the front drive line make sure the centering ball and socket are not worn. Most people never grease this item and by the time you figure it out it's too late.