U joints come apart and driveline falls out

[ksujason]

I have had something strange happen to my 1998 K1500. I replaced the U joints a few months ago, and after they had been in about a month, the ujoint came apart causing the driveline to drop. The bolts were in place for the ujoints, and one of the caps was still there. The other cap was gone. I thought it must have been a fluke thing, so I put new u joints in. Again about a month later the same thing has happened. This time when the driveline fell, it broke off the front of the transfer case extension housing. The bolts and retainers for the u joint are still in place, and one u joint cap remains in place. the other is gone. The straps that hold the U joint in place seem tight. I just cant figure out how one of the caps is coming out allowing the driveline to fall.

Has anyone ever heard of this happening?

Thank you,