Just bought a 2000 F150 4x4, (260K miles, 5.4L Triton, 4 speed automatic) runs great except in 4wd the steering shudders making tight turns. Any thoughts what might cause that? Turns fine in rwd.
Are you on paved roads when this happens? Do not drive on paved roads in 4×4, they are not the same as AWD! You will destroy your drivetrain driving around in 4×4 on a paved road making turns.
The front and rear drive axles are spun at the same speed in a 4×4 truck, they can't vary speed between the two. When you turn, the front and rear axles need to rotate at different speeds, in mud and snow, the tires can slip and not bid up the drivetrain. On a dry road, the rubber sticks to the street, it binds the driveline, leading to the bucking and shuttering sensation you're feeling. You will destroy gear teeth, break drive shafts, transfer case chains... extremely expensive stuff to fix!
