I have changed these on three of my trucks now , once on my 625 cat , twice on my 550 Cummins , the Cummins I did around 400,000 Km and just did it the second time at 900,000. This truck has been heavy haul its whole life , loads from 50,000 -500,000 . It never ceases to amaze me the difference when I do it . One day the truck sounds like it wants to come apart climbing the hill , and I think maybe it’s time for a new truck, change the damper and it’s like a whole new truck.would suggest changing at 450,000 Km wouldn’t wait for it to be a problem
