My '98 has a turbo from Industrial Injection and it seems to have a shutter/studder in it. It doesnt do it all the time but when i lug the motor when im pulling the boost guage goes crazy and the whole truck shakes. It also happens if I flat foot it all the way through the gears and when it shifts from D to OD there is a long enough pause that it dumps the boost and once the shift is made and the computer realizes I'm still flat footed it tries to catch up and causes an imbalance of pressure in the turbo...I think. Could be completely wrong, Im new to the diesel world.

 

Thats compressor surge. Its hard on the thrust bearing and a good way of killing the turbo. Back off when it starts to surge, or get a looser housing for it so it doesn't do it. A tight housing on a 65mm turbine is notorious for surging.

 

I did some digging and found that my turbo is a 62/70 Phatshaft and that turbo combined with the 12v is notorious for this and the guys at Industrial Injection say they have 2 12 valves in the parking lot with the same problem pushing more hp and boost than I am and after 4 years still no problems. They suggested I throw more fuel at it.

 

Did you actually measure the turbine wheel? AFAIK, II only uses the 65mm wheel in the PS series, the 71mm in the SPS series and 73mm in the Silver series. Despite what II says, surge is hard on bearings and is a good way to kill your charger. More fuel will make it worse. More RPM will make it better.