I have a serious vibration at any speed (even about 25-30). It goes away if I get on the gas at low speed but at 50 to 65 it is pretty severe. It is still there at 70 but is doesn't shake the vehicle so bad. It is expecially bad when going down a hill. I checked drive angle and U-Joints, all is good. The truck is not lifted. I saw a post in which the carrier in the rear was broken and his symptoms are much like mine. Going to open the rear today and see. I have large amounts of fluid leaking from the TC (NP208-700r4). I found NP208-700r4 from a 87 3/4 ton, will that fit in my 84 1/2 ton? If it will, I will get it so at least I'll have one to rebuild without having downtime????? Can I check the fluid level on the transfer case?? Where is the fill?? Thanks, and if there are any other areas I should look to kill this vibration please let me know!!!!!!!