I have a 2003 Supercrew 4x4 that I bought used 2 years ago. When I put it in 4wd there is a noise and vibration which is kind of hard to describe, but the best I can tell you is that it feels and sounds like I have mud tires on, except that I hear and feel it under the front floorboards. Even after switching back to 2wd, the noise and vibration continued for the 20 mile trip home. I didn't drive the truck again until the next morning, and the noise and vibration were gone, although I didn't put it in 4wd. This is the first 4x4 I've owned in 10 years, so I'm unfamiliar with what I should normally feel/hear in 4wd. I'm sure I should expect some noise, but this just didn't sound healthy. Thanks in advance.

 

I am suprised no one has answered this question... I am having the same problem. Throw it in 4hi, drive for a little bit, the vibration gets louder and louder. Then put it in 2wd on the fly and this noise continues for a while. My vibration is cyclic, which to me means driveshaft.

My guess was universal joints on the front driveshaft, as 4wd does work, just with that vibration. I guess I should lift her up and play around down there . Anyone know how easily the driveshaft can be removed? I know the bottom unbolts, but I'm unsure of the top.