Rear end question

Will do, It's actually difficult to get it to the whining spot. It doesn't whine on accell or decell it's just in between, so I'm hoping it's the pinion nut loose.
It is when u get to a speed and let off to stay at that speed and barely press the gas. It's not a grind, its more of a vibration. Hoping you guys are right. Will get car back soon, will post pics either way.

That said, If the yoke is loose, what is the procedure to tighten it and keep it tight?
What keeps it tight? I couldn't find torque specs, so I lowered car to about half the cars weight on tires and firmly torqued yoke nut (up until tires started to spin)

Do I need to have someone stand on brakes and I hit it with Impact or is there a torque spec I can't find?