I started to notice a vibration in the 1700-1900 RPM range. Most noticible when the TC is locked in 3L and speedo is approaching 50MPH although it also does it in 4L when the RPM is in the same range. It doesn't appear to be load dependent. I just had the cam and injectors replaced last week; the axle and driveline U-joints replaced with Spicer's, and the Fronrt DS is removed so I can rebuild the double Cardan. Hubs are 5k old, tires are at 60psi. My concern was the damper but a visual says it's OK and the bolts are tight. Any help appreciated.