So I took the tcase skid plate off to change the tranny fluid as well as try and clean some of the rust off. After wheelin last weekend I noticed that when I let off the gas around 45-55mph there was a harder vibration then the normal engine braking. I am not sure if I have a SYE, but from searching around I assume I do not. I have a 95 4.0L with a 4' lift. Should I have a SYE? I just think that the vibration is occuring as the rear diff pitches forward and the angle of the driveshaft is off...on the right track? Also, I didn't measure when I took the tcase skid off and assumed that when I remounted, it would return to the previous angle. Any thoughts on some tests I can do to figure out the issue. Other than the vibration the rig drives normal.