I tried Timbrens on my previous 2500HD, quickly took them off and installed air bags instead. I did not like how the suspension response changed running solo. On smooth roads the Timbrens were not active just like normal. But as road conditions changed, suspension response became very unpredictable as one or the other or both Timbrens were active over some of the suspension travel. Air bags are always an active suspension component and you get to adjust the air pressure to suit the load, road and your driving preference.