Investigation today has identified a blown 15A fuse in the autopilot computer (not the external in-line fuse but the one on the circuit board). Replacing this fuse with a 20A has brought the autopilot system back to life but the noise remains. It sounds like dry bearings in the motor. The helm without the autopilot engaged is finger light and silent.

Question - can the top of the motor be easily removed (8 hex drive bolts) and does it reveal the suspect bearings?

Second question - can these bearings be greased to solve the immediate problem or can they be easily replaced while away from base?

Third question - any ideas who could provide the best JEFA support in Guernsey?

My autopilot DD1 recently failed 8 hours into a 3 day passage.  Not wanting to hand steer for 3 days, we turned back into a building storm and then faced 8 hours of 40kts gusting 50kts before finding a sheltered anchorage.

Jefa diagnosed clutch failure and we ordered the parts, but after removing the base of the drive it was apparent that a small white plastic cog had shattered.

With crew flying in to Malta, I decided to replace the DD (€3,000). I intend to try opening from the top to get access to the damaged part, but haven't done so yet. Access from the bottom was straight forward although I needed an impact driver for a couple of reluctant bolts.  Jefa assure me the unit is designed for owner maintenance.

Jefa don't have a service network so everything has to be sent back to Denmark for repair.  You may find someone who is willing to effect a repair, but it won't be authorised by Jefa.

Note that you are unlikely to have something as simple as a bearing requiring grease.  I think you may find similar issues to mine with a gear cog badly worn or broken.

I would strongly advise you to get this fixed unless you have a crew if gorillas willing to hand steer through the night!

I would also advise against increasing the rating of these fuses.  I believe that Jefa recommend a 10A online fuse for the DD1.  I have never had the autopilot fuse blow on the main switchboard so not sure what rating I have there.

I had the same thought re the fuses and put a 15A back on the board before retesting.The inline fuse to the autopilot computer was originally 10A IIRC and, on advice on this forum, changed it to 15A some years ago. The 15A board fuse must have been a quick blow.

Covid was happening at that time and so the first use was in December 2020 for about 70 hours on passage from Brisbabne to Sydney, and it worked very well, in some very windy conditions.

Since then because of COVID restrictions and I'll health the boat has done a lot less sailing, and the Autopilot used for less than maybe 10 hours. Most sailing was  racing, all hand steered.

Late in 2024 the steering was a bit "lumpy" which I assumed was organic growth in the lower rudder bearing, which has happened before, but this time much worse. An inspection showed the Jefa DD1 was jumping when boat was steering manually. I removed the link arm  and immediately the hand steering was perfectly smooth. It was not possible to manually move the output level on the DD1 with the Autopilot turned off. It should move quite easily. 

I removed the DD1 and checked that the drive clutch seemed to not disengage when power  was off.

I disassembled the Jefa DD1 and found a lot of corrosion, even though  it has never been directly exposed to rain, seawater or high pressure cleaning.

-Lower output bearing seized from corrision

-Clutch pins seized in housing because of rust on  iron bushes

-Planetary annulus ring could not be rotated in housing, because of rust and no lubricant used

- Pancake motor seized.. It cannot be rotated by hand.

-gearing generally in excellent condition, no sign of overload or wear.

-other bearings very rough turning

-Electrical glands not properly tighted, and no sealant used as supplied by the factory,  which they recommend for motor replacement, but don't do themselves  from new.

If there is any rust in the motor or other parts like clutch pins, planetary annulus,, bearings etc  then it will overload the pancake motor, or at least make a lot of noise and may make hand steering more difficult.

It seems Jefa design and assembly just doesn't seal the unit, so normal atmospheric  changes in barometric pressures, , temperature, and humidity causes water to be inside the drive and cause havoc with corrosion. It is very disappointing.

Cheers DJ