Hi,
Here is an earlier thread about this:
http://www.pprune.org/questions/4726...ransports.html
From what I know a yaw damper is not an autopilot component like you say. A 737 for example only has a 2- axis autopilot. This is why a 737 has a crosswind limit for autolands, because It doesn't have the ability to kick off drift before landing.