Aircraft yaws left in flight. Rigged rudder I.A.W. 172m service manual. Bent rudder trim tab back to neutral. Replaced rudder pedal nylon bearing caps on pilots side P/N S1675-1 & S1674-1. Replaced both rudder springs P/N 0310196-5 & -12. Replaced right rudder pedal on pilots side, P/N AP2000-01. Adjusted rudder cables to 6½" from rudder pedal pivot (center) to firewall. Lubed rudder pulleys. Install directional gyro adjustment knob. Bob McCammond A&P 2211795. Aircraft is determined to be in a airworthy condition at this time & request test flight for possible rudder trim adjustment. Bob McCammond A&P 2211795.