Help! I lifted my truck with a 2" OME kit about a year ago. It was more like a 4" lift given all the sag in the stock suspension but it looks good. It did give me some driveline vibrations which were worked out by shimming the transfer case down... or so I thought.

Now the vibration is back. It's more like a shudder around 25-30 mph /40-50 km/hr and then goes away mostly until it comes back around 50-60 mph / 80-100 km/hr. The manual hubs are usually unlocked. I pulled the driveshaft and checked that the angles for the drivshaft flanges are the same. The drive shaft was rebuilt and re-installed and I even drove it without a rear driveshaft in 4WD at highway speed. No difference.

It shook with two different sets of tires but I'm taking it in to get the current set (225/75 R15 snows on Toyota steel rims) checked for balance and run-out. I usually run 235/75 R15 Desert Dueler ATs on the factory aluminum rims. The whole body of the truck shakes and you feel it in your feet mostly. There's no real shake in the steering wheel or the gearshift. The shake is more pronounced when accelerating or decelerating at the problem speeds and it varies with speed, not engine RPM, as I tried the same speeds in different gears.

I'm stumped. Any ideas would be appreciated...

Thanks!
Sean.