Just replaced both front axle u-joints but still get a vibration and when I let off the throttle & get back on it I get a knock; thinking it must be the driveline u-joints: front & rear, any tricks? Thanks again ahead of time!

 

Put the emergency brake on and put block at the wheels, put the truck in neutral and crawl under it and spin the drive shaft back and forth gently and listen for the noise. Also grab the drive shaft and try to push it sideways and up and down and the U-joints and carrier bearing.

Also take the truck for a drive then bring it back and feel if any of the U-joints are hotter than the rest. This is not a dead give away but can give you an idea which one to go looking for trouble from.

 

yes try this, a little play in ur hands is alot under torque.