I have an 86' cj, 4.5" Rubicon Lift, 44 Front, 9" Rear, 36" TSL's, 6cyl, NV3500, Dana 300, CV Rear Shaft. At about 40mph and up the jeep is not shaking and not necessarliy vibrating, but the whole rear driveshaft and tranyy is rotating constantly. It doesn't feel like it's the tires, but I guess it could be. The driveshaft has been recently balanced and the rear is set up correctly (2* below directly pointing at rear of tranny yoke). I thought it might be a lose motor mount, but that isn't the case. The shifter is motioning left to right. doesn't seem to be as bad when its cooloer outside, but still there. Any toughts? I haven't installed my front shaft yet (not arrived yet), so I can't pull the rear and drive in front wheel only to see if it stops. Any help would be apprecitaed.