Garmin/Lewmar Autopilot Drive Overload Issue

[macca499]

I hope everyone is well. I finally got my new to me 2017 Bav 34 home late last night after a long but very pleasant day motoring at 7 knots from Carlingford to Carrickfergus. Everything is working perfectly with the exception of the autopilot. The boat has an exceptional suite of electronics, all garmin including a 1223 plotter, ais, ghc10 autopilot controller, garmin reactor and some other garmin bits visible in the device list screenshot attached.

I had a delivery skipper bringing the boat around from the South Coast of England, he encountered a heavy squal near Carlingford where the autopilot locked out and gave overload warnings. Prior to this he reported that the autopilot had given overload warnings 1 or 2 times in fair weather also but had been ok after and had worked fine mostly from Gosport to near Carlingford.

When I stepped aboard a few days ago, as soon as I connected my activecaptain app and accepted the suggested fw updates, I had to re-do the autopilot dockside calibration, this kept failing but eventually passed however I expected the autopilot to move the wheel quite a bit during the calibration when in reality it only moved a few cm.

We set sail and when I tried to engage the autopilot out on the water, it engages ok but within a few seconds as soon as it tries to turn the wheel it throws up 'Autopilot drive unit overload' warning and disengages, the conditions were benign so no heavy load on it. We had to manually helm it home which wasn't a big deal but I am keen to sort this as I don't see how I could ever sail single handed with it.

Today I crawled into the space behind the rear berth to see the rudder and autopilot setup, I am clueless about these things so please excuse my ignorance about the components but could see a part Garmin, part Lewmar setup with a garmin ecu And rudder sensor connected to a Lewmar drive.. On the thicker Lewmar rod I noted the connection to the bearing seemed off and the bolt & nut securing the rod to the bearing was loose, assuming this was the issue i pushed the rod back down over the bearing and tightened the nuts but it doesn't seem to have made any difference and the rod still seems to be meeting the bearing at a downward angle which i'm not sure is correct. I have attached some photos for reference but these aren't great due to the very confined space, god knows how the stuff was installed by an adult.

Any and all help or advice appreciated or recommendations for anyone in NI who could look at this for me.

 

[macca499]

Some more photos, green light is on at garmin reactor ecu, drive moves by hand but seems stiff, not sure if this is normal. Have a garmin agent coming to look in next week or two hopefully

 

[ducked]

Maybe try greasing all the linkages, initially with a penetrating spray grease (which might do some good even on nominally sealed and un-maintainable bearings.) without disassembly,

 

[macca499]

Maybe try greasing all the linkages, initially with a penetrating spray grease (which might do some good even on nominally sealed and un-maintainable bearings.) without disassembly,

Thanks Ducked will give that a try this morning

 

[Boathook]

A couple of pictures show a ball type joint at a funny angle. I would adjust the locknuts, etc to straighten up the joint as it would seem to be binding. Not to sure what part of the system it is though.

 

[Lucky Duck]

Off topic, but I’m intrigued by the displayed speed through the water!

 

[PaulRainbow]

A couple of pictures show a ball type joint at a funny angle. I would adjust the locknuts, etc to straighten up the joint as it would seem to be binding. Not to sure what part of the system it is though.


View attachment 196399

That's called a rose joint, i agree, adjust it as you say.

 

[macca499]

A couple of pictures show a ball type joint at a funny angle. I would adjust the locknuts, etc to straighten up the joint as it would seem to be binding. Not to sure what part of the system it is though.


View attachment 196399

Thanks, I have straightened it on the bearing and tightened the locking nuts which were loose but still the same, this is the second part of the Lewmar drive that connects around the rudder stock, the threaded rod then connects to the other moving part of the lewmar drive, unsure how this could be worked at properly without a skilled small child to crawl in and carry out the work but I’m sure the experts know how

 

[macca499]

Off topic, but I’m intrigued by the displayed speed through the water!

We were motoring up the Irish Sea from carlingford at the time

Off topic, but I’m intrigued by the displayed speed through the water!

we were motoring up from Carlingford at the time, 2700 rpm and should have had some tide with us and light to no winds against us, gps speed was constantly 1-2 knots below through the water speed

 

[Buck Turgidson]

Agree about straightening the joint and lubrication. How does the rudder feel when hand steering? It could be rudder bearings or any of the steering connections if it's not the ball joint itself. Other option is the actuator drive. How old? When was it last serviced? If you disengage the actuator arm and turn the rudder by hand it should feel almost the same as with the linkage connected. If it's much lighter the problem is the actuator (drive or connection) If the weight doesn't change the problem is more likely the steering system/rudder bearings.

 

[Rappey]

Rose joints can sit at an angle. They are used on some atv,s for track rod/ tie rod ends . Depending on suspension compression and steering angle it alters the angle the rose joint sits. For this application its not a problem.
My thought is the threaded rod that the rose joint sits at the end of - it looks like the rod may be dragging over the bulkhead . Is it snagging causing the overload ?
Area highlighted in blue

 

[Buck Turgidson]

looks like it has worn an angle into the collar from binding on the stud. Stud has a shiny rim. It could be an optical illusion.

 

[Rappey]

If the rod with nothing undone cant be rotated at all then realigned the rose joint. If the rod can rotate then waste of time realigning rose joint

 

[macca499]

If the rod with nothing undone cant be rotated at all then realigned the rose joint. If the rod can rotate then waste of time realigning rose joint

Thanks all for the suggestions, I have attached another photo from the stern looking forward which is hopefully clearer, to the left is the rudder and garmin rudder sensor then to the right is one half of the lewmar drive with the rose joint and the rod connecting to the other half of the lewmar drive. There is a few inches of clearance between the arm and the bulkhead, the end of the arm can move freely around the bearing even when the bill is tight and there is no tightening other than the bolt and locking nut top and bottom of the bearing. It is quite hard effort to move the lewmar drive forward and aft by hand, it moves ok when turning the helm wheel by hand, I’m scared to undo the bolts and try the wheel without the drive engaged in case I lose them in the ether, im thinking possibly something wrong with the electrical end of the lewmar drive but I can’t see the wiring to this or how it is accessed, probably need to wait for an expert to get onboard.

Thanks again

 

[macca499]

Very difficult to take good photos in the confined space but I removed a few ceiling panels in aft cabin today to access the lewmar drive unit, have attached some photos and link below if it works is the video of me moving the drive arm by hand, it looks like this drive

https://www.svb24.com/en/bavaria-integra-rotary-drive.html

Dropbox

 

[macca499]

Off topic, but I’m intrigued by the displayed speed through the water!

Sorted now - had to re-calibrate the paddle wheel on the airmar transducer

 

[macca499]

Ok as is the way with these issues, I have finally got my head around the autopilot and steering system after much poking around. It is a Lewmar Integra sprocket drive which turns a secondary chain attached to the steering system, most of the Lewmar parts in my original photos are the steering system and not part of the autopilot.

I have tested the system and it is getting power, also the clutch + and - cable are showing continuity but motor not turning the sprocket, Lewmar think possibly the gear box which has plastic cogs and can be overloaded so have ordered re a replacement gearbox for £270 from Germany which will hopefully arrive in a few weeks. Only other possibility is the motor itself which is more expensive at £800. Will update once fixed.

 

[geem]

That's called a rose joint, i agree, adjust it as you say.

It looks to me that the installation is not right. That rose joint will be binding on the bolt head and reaching the limit of articulation. I suspect this is where the overload is coming from

 

[macca499]

It looks to me that the installation is not right. That rose joint will be binding on the bolt head and reaching the limit of articulation. I suspect this is where the overload is coming from

I thought this at first and the locking nuts were slightly loose at the joint closest to the rudder but it all moves fine when steered by the wheel and the autopilot motor just turns a secondary sprocket behind the steering wheel which in turn moves these rose joints so I suspect it’s the motor itself or a part within now.

 

[macca499]

So just to close this out - I was struggling to get help with this from the manufacturer or independent engineers. I removed the drive unit from the pedestal in order to test it and take apart to find the issue, when hooked up to a 12v battery, the clutch and motor worked fine so I suspected an issue somewhere in the Garmin system. I reinstalled the drive yesterday and low and behold it worked, passing both the dockside & sea trial wizards for the first time in my ownership and a further sail of around 2 hours last night. What a difference a good autopilot makes when shorthanded! Anyway, glad to have it resolved, even if I don't know exactly what the issue was but at least I have learnt the ins and outs of my boat's steering and electronics systems. Also, have a quote from Jefa for a plug n play replacement drive unit if it does ever pack in in future, thanks for all the replies and suggestions.