Crankshaft dampner

[Mrkentee]

Continuing with my vibration problem:

At 65 mph, loaded, I put it in neutral, the engine went to idle and had the definite vibration. When I brought the RPMs up to 1000 it went away. So it’s got to be the engine. I’m thinking vibration damper, front motor mounts, or the clutch. Or...??

Could a dampener be bad that soon (3 years), or from the box? What about the air compressor?

[imalumberjack]

does it vibrate while parked at an idle?

[Waterloo]

Damper has a 500,000 mile replacement interval according to Cummins. I know when I replaced mine at around 700,000 miles it did smooth out the motor. It was the factory original.

It is a consumable, so if it is getting to that point in time, it is going to need to be replaced eventually. Might be worth a shot to replace.

[Mrkentee]

(01-19-2019 )imalumberjack Wrote:  does it vibrate while parked at an idle?

Not noticeably at 700 rpm idle. Up around 11-1200 it shakes a little.

They want $750 for one now. This one was around $500.

[ynot]

What's your idle rpm at? In my experience anything below 700rpm an they will vibrate a bit, my 871 an this 870 I have now were both like that. I was in a buddies truck with a new x15(bone stock) an it was set down at 600 an was vibrating the interior so bad it was embarrassing for a 120k mile w9, I bumped his idle up too 725 using the cruise switch it helped tremendously.

too check the vibration damper just put both hands on the side of the valve while its idling, an feel for a mismatched shake, the worse the damper gets the more noticable it is, itll kinda feel like the motor is moving in an S pattern with the front of the motor shaking more an the rear is being pulled along for the ride