There is a clunking sound and feel when my 2007 FX4 is in 4 wheel drive. This happens sometimes but not always on engaging or disengaging 4 wheel drive, as well at sporadically while driving along. I took it back to Ford on warranty with this problem last year, and after a few attempts I had them admit that something was wrong and they finally diagnosed that it was the front drive shaft that was binding where it leaves the transfer case, this was replaced. I have now put maybe 50km (max) on in 4 wheel drive and the problem is back. Any suggestions would be helpful.

__________________
2007 FX4 Ex Cab 4.0 4x4