Originally Posted by
samnelso
....It's either the steering rate as previously described, or just the kinematics of the linkages as they get to full lock. Around full lock the linkages lose stability as the tie rod begins to intersect the kingpin. It's hard for the servo to control at this point as there is no mechanical advantage. Hence, possibly you can turn the wheels farther by hand than the servo would if you're grabbing the tire....
You said perfectly samnelso.
osavage1, I would disconnect the servo linkage from the servo horn and move the steering by using fingers and see how far YOU (your fingers) can turn the tires using the ball cup (circled in photo) from the servo horn. See if you can get full lock, left & right, just by using your fingers.