Chevrolet Repair: binding/popping coming from rear-end, axle bearings, perfect shape

Question
I have a 1990 Chevy K2500 4x4 extended cab Silverado. It has a new rebuilt engine, rebuilt transmission, rebuilt front end, recently rebuilt transfer case, new front hub bearings, and just this past Sunday a new set of rear axle bearings.  Waht is happening is, after driving the truck for about 15 miles or so I get a ticking or whinning sound which seems to be coming from the rear end, the bigger problems comes when I drove slowly and turn the front like going up into my driveway.  I get a binding/popping of significant force from the rear end.  I had the brakes checked and they are fine, Ihad the differential checked by 2 different places and they said the gears are fine> I thought it was the rear axle bearings because when my front was going out they would start locking up after they were hot.  I replaced both rear axle bearings, checked the ring gear, which appears to be in perfect shape with no cheaps, excessive wear or any metals shavings in the case.  It is all back together and it is still making the popping noise after it whatever it is warms up.  It primarily does it when there is turning involved, pushing on the brakes does not have any effect on the binding. If I went out and drive my truck now it would not do it, I drive it to work about 15 miles and it will do it.  I have soo much money in this truck that I cannot sell it even if I wanted too.  The binding/popping accurs at the rearend and you can see the tire pop when it occurs.  When it happens every small rotation of the tire.  Do you have any ideas?  IN the past I have taken this truck in for varies problems only to spend lots of money getting things rebuilt and then that ends up not being the problem.  I can repair a great deal of things but I hate to guess again and repair something that does not fix the problem. Please help.

Answer
Ok. A couple of things I can think of, do you have a lift on the truck, if so maybe your driveshaft is binding up at the yolk. Another thing is maybe you have a spool or posi in the rear end that could be locking up. Usually a spool will pop the rear end around a turn all the time though. If you have a posi it might be too tight and when it warms up the clearances get too tight. Anyways though the problem is definitely in the axle housing.