Front Drive Shaft and U-Joints ??

[Northerner]

I have a loud clunking noise every time my truck hits a bump in the road. Also under accelleration there is a vibration only when 4WD is engaged. I have had the upper and lower ball joints replaced along with one bad u-joint on the driver's side 4WD knuckle. Now I can also hear a grind or howl when I let of on the fuel in all gears. I am thinking that the front shaft must be moving where it enters the transfer case. Has any one seen this? Do I need to worry about the tranfer case failing?

This truck eats u-joints,and lift pumps now its may have an appetite for my transfer case!

 

[TexBamBam]

I have the same problem... check the u joints and the flex part. Mine is on nation wide back order... big problem