I think it is cause by the air compressor inflating the shocks to the max. What is your opinion?
Ride is very hard, specially in the back. What is the problem? on 2006 Buick Lucerne
Without seeing it in person our opinions are based on your input----Is the back bumper higher than normal? If you try to bounce it does it have normal play/travel or is it very stiff? If your answer to either of these questions is 'yes' than I think you answered your original question ..............That's MY opinion and I'm stickin' to it!