Harmonic Balancer or Damper...

[Waterloo]

(02-27-2016 )Running rough Wrote:  Would a new vibration damper help with a slight uneven ideal in an 2005 Ih cm870 with roughly 350000 km on it?

At that age, and having the original factory damper on, which is more than likely dried out from age, I could not say that replacing it will solve your idle issue. But, saying that, I would say it is time for a new one. If it was my truck I would have it replaced. When I replaced mine it made a noticeable difference in smoothing out the motor, and my belt issues went away.