You're generalizing to make your argument - you posted in that thread as well (His forum name is DJeazie). How do to KNOW that it isn't the same problem? We don't - you think you do but you don't; you're correct it could be installation error or he could've just had a really weak set of factory UCA's, or a bunch of other variables.
The point here is that there have been a number reports of Bilsteins popping upper ball joints on this forum and others. I don't think that they're all completing installation wrong. Zone's engineer whom I spoke with told me any lift (without drop - such as a level) in excess of 1" will eventually cause failure in the ball joint. Did you do the extensive testing that they did and not tell anyone? Numbers don't lie. As I said earlier, I suspect there will be several people that have argued over this on the forum asking about UCA's or quietly purchasing them down the road. I have no dog in this fight, I install all of my own stuff and have my Bilstein's set to 0.7" atop 4" of suspension lift (which drops components 6") - this issue doesn't even affect me. I am just annoyed at people jeopardizing the safety of others on the road because they apparently can afford a $30-$50k truck but whine about $420.
With the Bilsteins you are eliminating excessive down travel which certainly can damage the upper ball joint. But you are still lifting the front of the truck, even if it is in a more effective way; thus resulting in the upper control arm moving lower than it's original position and the ball joint shank moving to an extreme angle. Most guys were popping ball joints driving on normal roads, what do you think is going to happen when you head off-road and your suspension bottoms out on down travel? Yes a better scenario than with spacer blocks, I'm not arguing that - but you're probably going to make contact between the ball joint shank and housing, thus popping the ball joint.
Lastly, in regards to jacking the strut into place with the ball joint attached. I agree that it could cause damage but the ball joint shank would be pushed toward the center of the truck rather than toward the outside, which would cause the back side to pop - not the same thing. Please feel free to correct me if I'm wrong or not understanding your statement properly.
