I've had the TTHA-9602 kit for about a month. I like it and it rides great. I'm afraid its a little tall in the front even with the diff drop. Looks like everything is in a little bit of a bind. Had to replace CV joint also after about a week. I'm having a grinding noise in the front also...
Engage 4H
I also have the same vibration at 50 and above. After the install of toytec TTHA-9602 3" lift with diff drop. New CV's to no avail. Had read in another forum about it possibly being the front diff bearings. Suggested engaging 4H and see if vibration stops. I tried it sure enough...