Engine brake vibration

[trucklogger2]

Hello all- Cm871 bad vibration while using engine brake on high position when turbo boost reaches about 23-24 psi boost and above. Oddly it occurs only about 75 percent of the time.

It also has same vibration between 1500 and 1600 rpm on the go pedal on the way up through the range.

All sensors are new and both jake rocker shafts were changed six months ago which seemed to improve things a bit but is still mostly the same. I had a jobber rebuilt actuator on for 4-5 months and switched to an oem rebuilt actuator but that didn't fix the problem.
Tune is RRough

I'm suspecting turbo which is {non oem} reman on there about two years and can't remember if it was vibrating on old one or what the reason was for changing it then.


Another thing it does is when we go down hills on high position it will boost up to 30 psi but fluctuate up and down to lower 20's when its not vibrating {why I switched actuator}

Has around 10k hrs at moment and overhead done multiple times over last 2 years.
Anyways thanks; any help is appreciated