Help!

[Waterloo]

Dampers need to be replaced every 500,000 miles, it is a regular service item. There is a viscous fluid sandwiched in the damper, over time it hardens and throws the balance off. There is no way to check or diagnose that I know of, replacement is your only choice. Only use a Genuine Cummins Damper, around $650. Paint it before installing to keep the warranty intact. Use the expensive Cummins red paint, one can is plenty, around $30.