Having once flown a 707 all the way LHR-BDA with a yaw damper and autopilot that would not engage and encountered light and moderate turbulence several times on the flight, I would never accept a 707/737 without a working yaw damper. The dutch roll (corrected by roll inputs only) was most unpleasant for the pax, these were the days before modern flight recorders, but IIRC we got to 45 bank on several occasions.