Bilstein 5100 Struts & ShocksNoise

[CullowheeTB]

I recently had a ReadyLift leveling kit installed and at the same time had the shop install Bilstein 5100 shocks and struts.  The first few days were on usual pavement and the ride was great, with no new noises etc.  This weekend we took the truck to go for a hike and on the washboard dirt roads I immediately began noticing a 'hollow' kind of knocking noise, primarily from the front end.  After a few miles on the dirt roads the noise continued, but seemed to come from both sides, front and rear.  On the way home on pave roads i continued to hear the noise, although obviously much less frequent and quieter.

 

The noises definitely came when one or each of the areas of the suspension was either in the compression or extension phase of impact, hard to tell while driving exactly which but would assume it was during compression.  

 

Wondered if anyone with Bilstein's had experienced this as a part of normal operation, or if anyone had ideas as to the cause, whether it be the shock/strut itself or possible another component.  a quick visual inspection at the trailhead didn't lead me to any obvious causes.

[Sierra Dan]

The top hat nut is not tightened enough.

It needs to be tightened further once installed with weight on the truck.