Just finished up rebuilding my YJ. one of the things I did was install a advance adapters SYE and a Tom Woods C.V. driveshaft.
no vibration until you get it into 4th gear. Then smooths out once I get going above 50 mph. goes away when I push the clutch in. You can feel the vibration on the transfer case shifter. The transfer case shifts smooth in and out of 4wd and 4 low. I also installed a front posi lock at the same time but that seems to work alright.I have a spare transfer case and stock driveshaft that I am going to swap back into to the jeep. I will not be able to get gack to it until a couple weeks,due to customers work comes first. Anyone ran into this problem? I am confused the sye, swap is pretty straight foward but I could Have made a mistake somewhere. Any and all input would be greatly appreciated.