Dave merrick

I have a 2018 Chevy Silverado 2wd so when I go forward or backwards I get a clunking noise I have already had it service once and Chevy dealer said they loosen the Bolts and put grease in between the leaf springs and tighten everything back up it works but it’s at it again the truck only has 9700 miles on it I had a 2010 Chevy and never had this problem and it had 113000 on it I am getting tired of this 2018 truck