As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF ROLL IN PHX THE AIRCRAFT HAD A FAST BUT MOMENTARY UNCOMMANDED RUDDER MOVEMENT AT APPROXIMATELY 115 KTS. THE FIRST OFFICER WAS FLYING AND HE THOUGHT IT WAS A NOSE RIGHT MOVEMENT. PER LOG PAGE 4854424, REMOVED AND REPLACED LEFT YAW DAMPER. OPS CHECKED GOOD.