I have an 84 Toyota pickup 4x4 and just yesterday I noticed that when I would take off from a red light or just from a stop in general, something would shake for a couple seconds and then go away. It doesn't do it when I'm driving or slowing down, only when I first take off. The reason I think it is in my rear end is because I replaced my pinion seal yesterday. Now I don't know what I could have done to cause that but I'm thinking maybe I tightened something to tight? I really don't know. Any suggestions?