89 cherokee nv4500trans. I had bad vibrations and my rear ujoint was shot. I replaced it and inspected and greased the other ones which was about a month or so ago. Now um getting vibrations again. I happens in 5th gear. I put it in 4th same speed it goes away. Then sometimes there is no vibrations it runs smooth as butter in 5th. What is the next step? i go to silver lake in a month. Or should i even worry?