Join Date: Mar 2015
Location: Fort Walton Beach Florida
Several months ago, my 2015 Z71 did the same thing the clunking noise going over bumps and hard accelerating 45 - 60 mph and such. took it to my dealer, they test drove it and said that indeed it was bad off, loosen everything and retorqued it, tested again, still noise so ordered new right spring, tested again, fail, ordered again, that one fixed it. now it like new, and on top of that it helped fix the transmission problem i was having. they said that the isolator strips were bad like they were worn out. but yet they were new.
take your truck back and tell them to check again and replace the spring pack. might be the right side because that is your main drive wheel with all that torque, mainly on the right side..
2015 Colorado Z71 Red Rock Met. 2WD V6 EC TTP Nav Bose