Trim Tab Trouble

[mbird]

Hi All

The new boat I think may have a slight issue with a trim tab. These are hydraulic Eltrim tabs, and I have checked both oil levels which seem to be fine. The starboard tab operates fine, but the port tab seems a bit sluggish to react, but also will not fully retract. Though I haven't yet driven her at speed, when the boat was being demo'd on the river trial, there was a marked list to starboard on the first couple of runs, until the guy who took us out fiddled with the tabs. I now think this may have been the cause, and he corrected it by lowering the starboard tab to compensate.

The tab fully extends okay, albeit a little slower than the starboard one, but when retracting, it stops with three lights still showing on the display. Is there anything obvious I should check first (like a limit switch?), or is it more likely to be a bent shaft on the hydraulic ram?

Any help for this tab numpty gratefully received

[Brian]

I fitted Bennet trim tabs to teh bayliner, it had one motor, ( pump) is yours the same mark ? having one motor

[mbird]

No Brian, they have individual pumps and oil resevoirs for each tab.

[RedRover]

I would'nt be surprised if it weren't just due to lack of use,funnily enough mine used to veer to the Portside,in the end i had fitted Bennett electronic trim tabs where the motor is hydraulic and inside the engine compt(easier to overhaul) .the Volvo motors on the Sealines are on the actual tabs underwater.

[Antares_9]

It could be a number of things Mark but the symptoms you give are a bit like fouling on one of the rams, can happen if the tabs are not retracted fully after use.

[Guest]

Hi mark...

somewhat familiar with the starboard list experience from our old S28 (now gone...sniff!) which were renowned for this problem , I think we can offer some help...as could senator, who knows a great deal more.

Firstly, are you talking leg trim or tab trim, as the Eltrim trim tabs were operated by electric motors on ours, but obviously the legs were hydraulic.

I may be wrong but I think your legs are hydraulic and your tabs, electric.

At slower speeds, our experience was that neither made much effect on the tilt that the boat naturally had (in our case), but getting up on the plane was...er somewhat scary. We did however find out when she was surveyed for sale that a large part of our port duoprop was missing, and regardless of tabs and leg trim, the boat veered dangerously to starboard and couldnt be corrected by either leg or tab. The marine engineer still got her up to 32.7 knots albeit I was clinging on for dear mercy!!!

My suggestion would be to take her out on breydon on a good day and find the best combination of settings between legs and tabs, as they will all have an effect at speed....perhaps some more experienced members here can give some help with the best starting position, as we always had to overreact in panic when trying to compensate for the list, and as yet, due to the prop fault, never really got it right.

From personal experience, should you find this happen, dont wrestle with it...pull back the throttles, slow down and start again...otherwise, I will have no marker posts left on breydon!!

adam... : : :

[Antares_9]

Just re read your post and see that they are Eltrim Mark, to the best of my knowlege they have never made hydraulic tabs but like my Lencos they are electro mechanical.

Have attached the wiring diagrams for the auto and standard versions if they are of use.

Wiring+Diagram+automatic.pdf

Wiring+Diagram+ST.pdf

[senator]

Hi Mark,

The resevoirs you have are for the power trim on your legs, the mtors for the tabs are attached to the tab themselves and are an electric opperated worm drive withing the grey leg attached to them. Unfortunately there is nothing you can do with it once water has got in and corroded the worm drive but to prevent it happening to the new one change the little rubber bellows where the arm enters the housing when you change your anodes.

They are £110 each and simple to change, did the one that had gone on Clanny while she was still in the water.

the normal thing that goes arethe buttons on the control unit but these can be changed for about £10 all in, check the electrical supply before changing the motor to ensure you are not getting an intermitent supply, from what you describe though I would give trickett a ring.

Unfortunately tab problems are common on sealines our age but at least they are fairly cheap and easy to sort out and should then be good for another 15 years

http://www.trickettmarineproducts.co.uk

Ian

Edit to add: Sorry Mark, have just checked the price, must be down to the weak £ but they are now £160 Plus VAT and Delivery.

That is one hell of a price jump in 15 months from when I bought mine.

[senator]

Might be worth a call to Nick at Seabridge Marine, when I bought mine he was slightly more expensive than Tricketts but he is also a great source of parts for older Sealines, if he can't get it you no one can, he is also a massive font of knowledge, really knows his stuff.

Ian

[mbird]

Hi all

Thanks for the pointers. Adam, I was definitely takling about the tab, not the legs, as those work perfectly from -1 to +40. I may have mislead everyone though, saying they were hydraulic, as I just assumed the resevoirs and pumps I could see, that are right in the coreners of the transoms, were for the tabs . I need to check properly when I can get down to the boat after this cold stuff thaws out!

I think I'll have to try just working the tab up and down with a little manual pressure on it at the same time to see if it is just growth, but the fact it operates a lot slower than the other one, and then stops dead before it is fully retracted (and always at the same point), does indicate a mechanical rather than electrical issue methinks.

Maybe a lift after NYE is on the cards after all.

[senator]

Mark,

You can change the motor while the boat is still in the water. As from what you describe it is most likely to be corrosion on the worm drive then it would be cheaper to bite the bullet and buy the motor, that is unless you were going to have her lifted anyway.

Ian

[mbird]

Mark,

You can change the motor while the boat is still in the water. As from what you describe it is most likely to be corrosion on the worm drive then it would be cheaper to bite the bullet and buy the motor, that is unless you were going to have her lifted anyway.

Ian

Oh I see. Sorry Ian, I misunderstood and I though you meant you could change the bellows. I wondered how you did that without getting them full of water . I suppose by the same token, it is also easy enough to remove the motor from the tab and just see what it is doing then?

How are the motors fixed, is it nut & bolt or a pin with split pins?

Think I'll wait for the water to warm up a degree or two first though!

[senator]

Mark,

It is a pin with a split pin in the end where it attaches to the hull and a nut and bolt where it fixes to the tab, the wiring is 4 or 5 wires that will connect inside the boat and it comes in through the little chrome hood you will see above the water line next to the tab, this should be siliconed but mine pulled through fine..

The top pin is above the water line and the bottom fixing you need to feel for but it is only a couple of inches down. Did mine by deflating the dinghy so I could get under the bathing platform.

Good idea to wait till it gets warmer though.

Ian