Timing marks illegible

[Waterloo]

Start with a wire brush and sandpaper... You will need to be able to bar the motor to get to the actual timing marks. Once clean, I would paint with something to mark them for the next time. If the truck has over 500,000 miles, Cummins recommends changing out the damper, as the internal viscous fluid that handles the balancing act hardens over time. So, not knowing how many miles on your truck... A damper runs around $650 to $700 not including install. It needs to be painted to initiate the warranty.