Instructions for stripping down a Lenco Trim Tab Actuator - with Photos

oGaryo

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Firstly, please bear in mind doing this will affect any warranty on the actuator but if out of warranty there's no loss there.... these things are most definitely servicable units!

This guide is for errrm, guidance only, and is based on my limited experience. I'll hold no responsibility if I've missed something that costs you something or you injure yourself.. knives are sharp boys n girls and tend to sting a bit if you stab yourself with one, use something else if you're prone to cutting yourself:D

With a price tag of £180 in the UK, well worth the effort to repair:cool: 30 mins to remove from the boat and max, 30 mins to effect the repair for the fault I came across.

Step 1:

remove the actuator from the boat as described by many posts on google and the Lenco website I believe... for me, I cut the cable (just two wires inside) so I didn't need to pull several metres of cable through a very tight wiring loom.. I'll refit with push connectors and seal with electrical tape. I also removed the triangular mounting bracket from the top of the actuator (plastic rod tapped out with a thin screwdriver to do so)

Step 2:

You should now have the actuator removed from the boat to make it easier to work on.

Remove the 2 x domed nuts and the compression joint for the cable entry on the top of the actuator cap... I also removed the part of the compression fitting from the body of the unit to aid removal of the cap (see step 3, less friction from rubber grommets and cable entry joints = the cap comes off more easily).. it can be removed with a spanner and can be seen in the top left hand corner of the photo below.

this photo shows all components laid out to aid with understanding the subsequent steps...

CIMG0163_zps6060cba2.jpg


Step 3:

The unit is still whole so we now need to commence dismantling it to make it look like the above photo.

To remove the top cap, I took a strong but thin none cerated sharp knife (I used a filleting knife) and slid it in between the top cap and the main body of the actuator, lengthways not pointy end in first... you can gently prise the cap off the main body by working progressively around the circumference of the cap using as much surface area of the blade as possible... be careful, once you have the cap off enough to get a blunt knife (or the back of a sharp one) in there, do so.. there's a rubber sealing ring that could be damaged with the sharp edge of the blade as it becomes exposed, see photo below.


This photo shows the top cap removed where you should just be able to see the rubber sealing ring and also the brown stains showing where water has bypassed it.. You'll also note the basic means of making the electical connection to the motor.. this was the reason for my actuator exhibiting a fault (no movement but still had power drop on pressing the button), one of the connectors had corroded making for a poor contact.. a quick clean with wire wool and we have a working actuator again, simples!!!!

CIMG0164_zps56ac7a29.jpg


Also note only one domed nut is shown, I chucked the other as it was corroded and was the cause of the water ingress as it didn't keep the top plate tight against the main body of the actuator. It also shows washers and rubber grommets that I also removed to aid the removal of the top cap / plate from the main body as mentioned in step 2... the rubber gromets sit in a recess so take care removing them if you do the same as they'll be easily damaged, resulting in water ingress on refitting.. I will replace mine.

Step 4

once the top cap is off, it's a simple case of pulling down on the lower section by hand to separate it from the main body.. no need for prising off, it'll saperate easily if you wiggle it and you pull.. the two rods in this photo extend through the main body, then through the top cap and ultimately, to the two domed nuts.. check the tightness of the two little nuts as part of your maintenance programme, if they become loose, that is when water gets in as they hold the whole unit together. I also advise you keep them protected from rust with antifoul paint.. whilst my fault was a poor electrical connection, the root cause was a rusted nut that worked loose allowing the water to come in to the main unit!!

Lower unit removed

CIMG0165_zpsb7fd3ea3.jpg


Step 5

and that's all there is to it really... a case of fixing whatever it is you find and putting back together in reverse order taking care not to damage the sealing rings and making sure the cogs in the gearing sit in their recesses in the main body (see photos below). I will be regreasing the cogs and cleaning up the contacts, this time protecting them from corrosion.. I'll also replace the rubber grommets as said above and domed nuts to ensure there is no water entry point via that route. I won't be putting any sealant on the joints as that will make it harder to disassemble should it break again, they will be left dry relying on the rubber sealing rings to do their job but as said, I will be making a better job of protecting the electrical connectors as that seems a weak point in the design.


A few more photo's with pointers to help put the unit back together and also show other components can be replaced easily if needbe e.g. a burnt out motor.

Photo's

central cog in the main body that drives the gearing made up of 3 x cogs in the lower unit.. note the 2 x screws, undo these and the motor can easily be removed from the main body for repair if needed. I'll put up another photo later in the guide as there's a few holes that need explaining.

CIMG0166_zps55788c24.jpg


rubber ring that seals the lower section to the main body of the actuator.. no water bypass on this one.. the same type and size sealing ring that's used to create a water tight seal between the main body and top cap.

CIMG0168_zpsb7d62168.jpg


plan view of the main body with the central driving cog again.. the two rectangular holes are where the rods go through the main body to meet up with the top cap and domed nuts.. the two circular holes (one covered in grease) are where the cogs in the lower gearing seat.

CIMG0170_zps6b316a09.jpg


top section of the main body showing the motor and the water damage (only slight).. still very much a servicable unit.. note the red dot, this is the connector that the black wire needs to connect to

CIMG0171_zpsdf35719f.jpg


and finally, a plan view of the lower section showing the gearing clearly and also a central screw.. I've not undone this as I don't need to but presume it allows access to or frees the actuator ram should it or the seal to the ram need replacing

CIMG0172_zps8a30ddcc.jpg


Hope this is helpful and this saves someone a few quid... it did me!:cool:
 
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EDIT: ignore the bits above about removing the cable compression fitting if there's no problem with it, in hindsight, the top cap can be removed as described and then pull the push fit connectors off the motor leaving the cable entry untouched
 
hi gary..... GREAT REPORT N PICS !!!!!!!.... just for your interest, the plumbing and gas fitting trades use a sealer on compression joints that is both water proof and never goes hard or cracks, BUT, i cant find my tube so i cant give the name..hopefully someone will post the name !!!!!!
 
hi gary..... GREAT REPORT N PICS !!!!!!!.... just for your interest, the plumbing and gas fitting trades use a sealer on compression joints that is both water proof and never goes hard or cracks, BUT, i cant find my tube so i cant give the name..hopefully someone will post the name !!!!!!

good call Steve, I have some locktite sealer that does the same, think I used it on the exhaust risers or something on the old boat... will give that a go
 
Nice post Gary, my little motor is fried (water got to it) did you just clean it? did you buy a new one? I can't find a motor like this for sale.

It is ridiculous how Lenco doesn't sell parts of the actuator, it is the VERY simple to service it.
 
Hi Gary,

I have the same Lenco Trim Tabs on my boat (they are at least 15 years old) and last week the port side T/T stopped working, the motor just stopped running. After checking the switch and wiring with no resolution I decided to disassemble the actuator to investigate further. I took everything apart on the top end including removing the little motor and gave everything a very good clean as it was pretty filthy, lots of dried greasy sediment inside the housing and around the motor but no real evidence of any major corrosion. The motor appeared to be a little "frozen" as it was hard to rotate the motor when trying to move the cogs with my fingers. I am kicking myself that I didn't apply any power to it from the bench at this stage. Anyway the clean up worked in so far that the motor can now be turned with my fingers manually and when I apply power it is definitely working on the bench.
I also removed that central screw to clean the bottom cog and discovered that the screw connects this cog directly to the top of what I suspect is a threaded shaft inside the RAM that rotates clockwise and/or anticlockwise to lower and raise the Tabs. On reassembly for some reason I couldn't fully tighten that screw so that it would sit tight and flush with the cog. It goes in about half way and then meets with some resistance and then starts turning the shaft, which retracts a few millimeters before just rotating clockwise. (as an observation, if the screw was flush with the cog the shaft could not retract at all as the cog housing would prevent any movement). When I turn the screw anticlockwise it retracts the shaft, just for a few turns and then the screw fully unwinds and comes out, thus the bottom cog is no longer secured on the shaft. Although I was somewhat puzzled about this I reassembled the Actuator for a bench test and whilst the motor whirred and no doubt some or all of the cogs were moving the RAM did not move in or out on either polarity. So I disassembled the actuator again, stripped it right back and lightly applied my power drill with a Philips screw driver to turn the central testing in both directions, by passing the cogs altogether. The shaft turned both ways but the RAM did not move! This all seems a little odd and I am reluctant to try and disassemble the bottom half of the actuator until all else has failed. Any ideas?
 
Brilliant of how to do, with pictures.

Having taken my Lenco actuator off finally as she been lifted out for maintenance.

It appears to have been the terminals the cause for the motor not working.

Having cleaned the the spades on the motor and replaced the female crimp terminals.

Any suggestions of how to help prevent corrosion of the terminals again.

In addition, a fellow boater next to where my boat is laid up suggests putting Anodes on the trim plates. ???

Thanks
 
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HI

Does anybody know where to find the gears as spare-parts? Lenco only sells complete actuators but I would only need a couple of gears
 
hi gary..... GREAT REPORT N PICS !!!!!!!.... just for your interest, the plumbing and gas fitting trades use a sealer on compression joints that is both water proof and never goes hard or cracks, BUT, i cant find my tube so i cant give the name..hopefully someone will post the name !!!!!!

Fernox LSX
 
Nice post Gary, my little motor is fried (water got to it) did you just clean it? did you buy a new one? I can't find a motor like this for sale.

It is ridiculous how Lenco doesn't sell parts of the actuator, it is the VERY simple to service it.


It depends where you are based. I got the motor from my (original) Autohelm re-wound by a firm in London.
http://www.robsonandfrancisrewinds.co.uk
 
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