Vibration/shaking at @1500 under boost.

Trees, that's what the Kenworth dealer that has done all the work is saying, but cummins says that it is impossible seeing as they are internally balanced engines and they recon that if it was a crank it would vibrate all the time even when just free revving, not just under load.
I just replaced the barometric pressure sensor, no change

 

Process of elimination, it is the only thing remaining, although I think that it's more likely to be something with the clutch. A badly imbalanced crankshaft would cause an engine to fail, I'd think, if it was badly imbalanced. Anybody send a used engine oil sample in for analysis? If it was the crank I'd expect to see wear metals way up in a UOA.

 

I'd be checking all the tail shaft angles. If it was My Truck..

http://spicerparts.com/anglemaster/measuring-angles

 

Sorry leftlanetruckin I didn't mean to hijack your thread.

Yes oil samples have been done on engine and gearbox both came back fine. Driveline angles have been checked and the drive shafts have been balanced. It has had brand new friction plates put in and then a whole brand new clutch as well, no change, new flywheel, no change.

I personally think it is fuel. It happens in every gear no matter what speed you are doing, as soon as you put fuel into it and it comes on boost it happens and as soon as you let off it's gone. I actually think that since I have done the barometric pressure sensor that the engine has smoothed out a lot and is running better but the vibration and noise is still there.

If it was driveline it would usually happen at a certain speed not in every gear. The noise from outside the truck seems to disappear at 1800rpm every time, the vibration is still there but the noise goes away. It is very weird. Even 2 cummins engineers that have looked at it are stumped.

 

Probably not your problem, but an exhaust restriction will cause that same kind of vibration.

 

Say, like that of a DPF?