EV 100 clutch disengages itself

[garybuyit]

Last time out on the boat, the autopilot clutch lever "de-clutched" itself many times during a 4 hour sail. The lever simply moved up, away from the gears. Most times it didn't completely disengage from the gears, and we held course. However, if I didn't notice it right away, it would fully disengage, and the boat started wandering off course. It did this every few minutes. Has never happened in the past. Under sail, not power, downwind, 15 -- 18 kts. of wind. Coming home two days later, it happened a couple dozen times during the 4 hr. sail. Again, under sail downwind, with 12 -- 14 knot winds.

This is a new autopilot, installed February 2015, has worked flawlessly until 2 weeks ago when the problem occurred. The boat is a Nonsuch 33, 15,350 lb. displacement.
Nothing appears to be loose on the autopilot ring containing the gears, or the clutch lever itself. When I engage the clutch, it goes firmly into place. Where do I start troubleshooting?
Thanks,
Garybuyit

[Chuck - Raymarine - Moderator]

Gary,

General Note: for the benefit of others who may be viewing this thread exceeding the maximum displacement recommendations for an autopilot may
- adversely affect the performance of the autopilot,
- result in reduced autopilot drive unit and/or ACU life, and
- potentially void the product's warranty.
The maximum recommended loaded displacement for an EV-100 Sail Pilot is 7500kg (16,500 lbs.). The specifications for the NONSUCH 33 sailboat indicate an unloaded displacement of 15,350 lbs. The normal rule of thumb is to add 20% (sails, ground tackle, lines, fenders, fresh water, provisions, holding tank fluid, fuel, passengers, etc. ) to this number to determine the vessel's loaded displacement. This would bring the sailing weight of the vessel to 18,420 lbs., which is almost 2,000 lbs over the maximum recommended displacement for an EV-100 Sail Pilot. In this case, a below decks autopilot would be recommended for this sailboat.

Please click here to view a FAQ addressing how to adjust the belt tension of a Wheel Drive.