Hi! I have used my Bilstein coilovers for 9 years on my Sierra 4x4. I had guite hard setting on springs and dampers, but never any problems with the turrets collapsing or things like that. The problem with the springs touching the inner wing is right. I had to "massage" the inner wing a bit to get clearence. Now i don,t have these problems any more because i have changed to Proflex and they have a smaller diameter spring at the rear, and they are adjustable which i really looking forward to, to be able to adjust it for road use. Sorry for my bad Wnglish, I.m from Sweden! Johnny.