I did replace the internal planetary gears in the autopilot linear drive in Nov 2001 while in Cabo San Lucas. They failed due to stupid operator error when we had to make a sudden night time departure from an exposed anchorage (San Carlos - north of Cedros) that suddenly had 10' breaking waves. The new gears are bronze.

Raymarine tells me that the new course computers are compatible with the old linear drive motors but are NOT compatible with the ST6000 control head I currently have. That means if I have a spare autopilot computer I also need a spare/NEW ST6000 control head.

Brian - what is your understanding of the compatibility of older STxxxx control heads with new course computers? How many hours do you think you have on your linear drive motor?

We have two backup steering systems - a Sailomat windvane and an Autohelm ST1000 tillerpilot that can drive the windvane.