Harmonic Balancer or Damper...

[Waterloo]

For you guys with older trucks, it is recommended that the Harmonic Balancer/Damper be replaced at 500,000 miles. I replaced mine at 700,000 miles after figuring out it was bad on my 2008 Cummins CM871... The Balancer/Damper is the big chunk of metal, the round disk, that is installed at the end of the motor's crankshaft on the outside of the motor. I figured out mine was bad when I kept popping belts, lost the tensioner, then the alternator and AC compressor. All of this happened at the same time and I was like WTF? I did some reading and discovered that these balancers go bad and cause these very issues. There is a viscous fluid inside of these balancers, that after time and use hardens and renders the balancer useless. Imagine what is going on inside the motor if a bad damper is doing this to your accessories and belts?

I went with the OEM Cummins balancer/damper, it cost $635 at my Cummins shop, the install was another $500 for labor. It was winter, temps running in the teens, I am not doing this in my driveway. Anyhow, I took the truck in on a Tuesday evening and got it back the following morning. I fired her up and thought WTF? Am I in the right truck? The motor was much smoother, to the point I thought they through a new motor in! That was what, two years ago? Everything has been fine, no more popping belts or failing parts.

So, if you have a motor at that 500,000 mark or better and have not replaced that Damper/Balancer, it would be a good time to seriously consider having it replaced. Sadly, there is no way to diagnose a bad or worn out balancer, replacement is the only option. If you are going to keep the truck, I would highly suggest getting this done.

Hope this helps!