Clunk noise when shifting upwards

Hey guys. Ive been thinking about this for a couple of days and think Ive come up with a theory.Some of you have noticed that there is some driveshaft rotation with the trans in Neutral and parkbrake applied or similar circumstances, right? Well,as I followed the chain of parts I concluded that most of that "slop" originates(open diff now) in the interface between the side-gears and the spider-gears. Imagine that the diff cover is off and youre looking into the case window. Imagine that the side-gears are anchored and cant move. Now imagine grabbing the ringgear and turning it back and forth, that is,pushing it up and then down. While doing this watch the spiders. They will be climbing the sidegears till they run out of room, then falling to the bottom of the sidegear and then climbing up again. Now, keep that action in your head for a bit. Going back to the lift-foot upshift, try to imagine whats happening.AS the car is accelerating, the spidergears are jammed up to the limit under torque from the engine. then as you lift off the gas a moment occurs when the engine goes into zero torque or even compression braking. Well the spiders drop down or even climb up the otherside of the sidegears. Then the shift occurs, and torque is definitely going negative(foot still off gas). I think all this spider action is producing the clunk. Of course under normal acceleration there is a continuous torque applied and no clunk is felt/heard. This is also why it clunks, going from Neutral to Reverse or Drive. So whats the cure? well number one is to remove and inspect the crosspin. They have been known to egg-out the case and also the spiders wear deeply into the side of the pin. Then the rest of the wear needs to be shimmed out; either thicker washers or extra washers or new parts. As said earlier this applies to open diffs only, and this is my theory as based on observing my /6,open-diff, Volare.----- So, any comments?