Anybody out there with some moderate to extreme mods have any problems with your stock fluidampr? I'm wondering how much tq and hp changes the stock damper.

 

I don't understand your question.
Fluidampr is not an oem product. The vibration dampener on the Cummins is not a Fluidampr. There is a replacement dampener (harmonic balancer) available from Fluidampr.
If you are having problems with the oem dampener, it is usually due to higher than intended rpm's, or high mileage. It is also reccomended to be changed every so many miles, I think around 250k, but check the service manual. If the rubber has deteriorated it's bad and needs changed.

 

both of mine are still stock, and ok, 320k+ on the 75 and 200k+ on the 98