The outfit below seems to be bottoming out much harder than it used to this season. Pot holes or sharp bumps in the road produce very jarring results,very quick rates. The shocks are Bilstein ...
Bilstein 5100 shocks are lifetime warranty. http://cart.bilsteinus.com/pdfs/limitedlifetimewarranty.pdf see above pdf file to claim warranty. I have replaced Bilstein 4600's on my wifes 1996 Toyota 4 runner under warrant after they were 15 years old. I have the same 5100 shocks as you ,originally purchased for my 2011 GMC 2500 hd. used them for 75,000 including a trip to with truck camper to Alaska. Those original shocks are now on my 2016 GMC 3500hd . Still working great.