It still drives in 2wd, but makes a drive shaft rpm vibration in 4wd. probably a bearing. It might actually be a u-joint, but can't seem to see a problem. will know when it starts to get torn down.
My 2003 Rubicon is my daily driver. its the gold03 in gold03. I love that thing. now it just needs to get some wrench time after 200,000 KM. It is still on original u-joints up until two weeks ago. I haven't had to replace anything on it. Its just due. It does not see serious off road, but it does see off road a lot. I don't abuse my vehicles.
I love driving back roads and off roads. This thing has many subtle changes that are hard to see but make it very capable off road.
gold03