Tab replacement

H

hrynyk6

New Member
Feb 26, 2011
75
Michigan
Boat Info
1993 370 Sundancer
Engines
454 Blue Water
Hello,
I have a 1993 370 Sundancer that is known for having a heavier than Kim Kardashian rear end. To make matters worse, I'm going to start transporting my RIB dinghy with a 9.9 4 stroke Merc. horizontally witch means that even more weight will be transferred aft.
I'd like to switch my original 30" x 8" Bennett tabs with 30" x 12". My questions are 1). Will the 12" tab have the same mounting location for the actuator? 2). Can I re-use the same actuator & hinge?

Thanks, Dwayne
 
Dwayne,

The answer to both questions is yes, and it is a great idea! To be certain you say that your Trim Tabs are 30 x 8. I think you actually have what we call 30 x 9 Trim Tabs. The actual fore to aft measurement is 8-5/8" and the trailing edge is folded up where the actuator attaches.

The 12" Tabs have the mounting point for the actuator 8-5/8" out so they can be fitted without moving anything.

If you want the maximum lift possible you can consider using 30 x 12 Trim Tabs with Drop Fins. Drop Fins extend 3" down on each side of the Trim Tabs. They capture water pressure that normally escapes out the edges and channels it aft to increase lift.

Here is a video of a boat with Boat Leveler brand Trim Tabs being refitted with Bennetts with Drop Fins so you can see what they look like http://www.youtube.com/watch?v=Crd5zFaihRY

The Drop Fin Trim Tabs will also fit right in place of your old Trim Tabs.

I hope this is helpful, let me know if you have any questions.

Tom McGow
Bennett Marine
 
Hi Tom,
I spoke directly to Bennett about purchasing 2 new tabs for my boat. I was supplied with the part # that I need and I was instructed to contact a local Bennett dealer. After emailing the only 2 dealers that are somewhat close to my location, I was informed by 1 of them that they only sell wholesale and I could contact the local Ace Hardware or O'Riely's Auto Parts to have them ordered for me. The other Bennett dealer listed on your website never contacted me.
Is there any way that I could order the parts directly from Bennett?
Thanks, Dwayne
 
Dwayne,

Have you tried BOE Marine? They are the sponsor of this forum and Jim is excellent at getting our parts at a great price with minimum fuss. Jim is a great guy, I,d give him a try!

Tom
Bennett Marine
 
Hi Tom,
No, I actually never even thought of BOE. I was looking for a local supplier. I will email Jim today, thanks for the reminder.
Dwayne
 
Hi Tom,
Jim at BOE gave me a great price for the TPO 3012 DF's!
I haven't ordered them yet because when I removed the existing actuators from the old tabs the trim planes won't slide out of the hinge in either direction.
I'm REALLY hoping that I dont have to remove the hinges from the transom, there's probaly 14 coats of antifouling paint covering the screw heads.
I had to use a sawzall to cut the head of the bolts off that attached the actuators to the tabs.
Any advice / suggestions would be greatly appreciated.
Thanks, Dwayne
 
Dwyane,

The Trim Tabs are not really designed to slide out of the mounting plates. There are small "keeper tabs" in the mounting plates to keep them from sliding out since there is a fair amount of pressure trying to slide them outboard when the boat is running. I am sorry to say the recommended method is to unscrew the mounting plates from the transom.

Tom
Bennett Marine
 
If you can't dig out the old paint (pick tool, razor blade, etc), use a small cut-off tool, like a dremel, and cut a "slot" so you can use a large, flat-blade screwdriver or something similar. Once you get them out, you can clean the area, use some good silicone (like LifeSeal, for example) and reinstall with new screws.
 
Hi Tom,
I removed my old trim tabs today and it went really well!!
My new question is that I realize that I have room for a 12" X 36" tab opposed to a 12" X 30" tab. ( I'm replacing the original 8 5/8" X 30 " tabs )
Will a 12" X 36" drop fin tab be too much for a single actuator?
Thanks, Dwayne
 
Rather than replace the original tabs, why not just add an extension to them? There's a company that makes larger tabs. All you have to do is hold them in place with clamps, drill a few holes and mount the new tabs to the existing tabs with stainless nuts and bolts.

I had tab extensions and an extension to the running surface on my boat when I had the extended swim platform put on. Here's what it looks like now...
This pic shows the extended tabs and the running surface extension from the top...
P7290011.jpg


and from below the trim tabs.
P7290012.jpg
 
Hello,
I appreciate the suggestion but I wanted to stick with a 1 piece tab and I'm switching to drop fin tabs for greater lift. I have an extremely aft heavy boat that I made even heavier with a new dinghy transporting system.
Thanks, Dwayne
 
Gofirstclass did similar to what I did. My 22*9 are now 22*18 with 2" drops on each side. All stainless and heavy as can be. A friend who drover her on part of a long trip a few years ago took her from my old marina to my new marina while I spruced her up during the trip said to me, "This is not the same boat I drove a year ago. What a difference."

Obviously your call, but something to consider. Mine were done by a professional welding shop.
 
mwph said:
Without hijacking the thread, Is adding an extension to the running surface a common practice? I'm just asking to learn, no other reason.
Click to expand...

I first heard about it on a Regal Owners site (no longer in operation). Saint Max was nose high on her maiden voyage home from NC to VA. I found from talking to other 330 owners that they had the same problem.

Doing some very dpmulvey simple math, the size of the tabs based on the Bennett sizing charts was inadequate. Because of the prop pockets, I could not get the span Bennett recommended. I went with length instead. The only fear I had was the actuator not being able to handle the extra size. To date, the only problems are to remember there is a lot more tab out there and a lot more reaction to each push of the bow down button. I also have to remember to retract the tabs before backing down to avoid undo pressure on the system.

Beyond that...no looking back.

My comfortable cruise is 22 knots. I now do that at 3400 RPM's. I used to have to turn 3800 RPM's to get there and was still nose high. I have cut fuel consumption, noise at the helm, vibration, etc......

Between the tabs and PropScan they are the best two additions I have made to her.
 
mwph said:
Without hijacking the thread, Is adding an extension to the running surface a common practice? I'm just asking to learn, no other reason.
Click to expand...
mwph, I'm not sure if it's common practice or not, but we were kind of forced into it. The boat yard in Portland, OR that I had recommission my boat when it was shipped from Michigan added several items to the boat and an extended swim platform was one of them. It's a HUGE extension and we really enjoy having it. The only problem was when we're coming up on plane the roostertail hit the underside of it and the boat yard owner thought that might create problems.

He's an engineer and got together with a nautical engineer to find a solution. They came up with the idea of extending the running surface and the trim tabs to give the boat some added length and (hopefully) push the roostertail further aft. Well it worked like a dream and we're happy with the results. Now, when getting on plane I don't have to use any tab at all and the boat comes right up on plane.

Here's what the swim platform looked like before installation.....
P70910131.jpg


Here's what the roostertail looks like now....
P80300271.jpg


and here's what the swim platform looks like....
ADSCN01672.jpg
 
Dwayne,

You can use a single actuator on a 36 x 12 with drop fins. You would need to make sure that the actuator is centered side to side on the 36" which may mean repositioning it.

Tom
Bennett Marine
 
Thanks Tom! Actually with the 30" x 8 5/8" tabs the actuar is off centered. By going to the 36" x 12" tabs the actuator will be centered! I love it when a plan comes together! BTW, what is the part # for the 36" x 12" drop fin tabs WITH the hinge & backing plate?
I'll order them from BOE as soon as I have the part #.

Thanks, Dwayne
 
Dwayne,

Sounds good. The Part Number is TPA3612DF, you will need 2 each. Let me know how it goes!

Tom
Bennett Marine
 
Hi Tom,
I received my new 12 X 36 DF tabs today. I'm impressed! Even the screw holes match my old tabs, I'll only need to drill 2 extra holes per tab. I'm planning on installing the new tabs on Wed., March 28. I'll let you know how it goes.
Thanks, Dwayne
 
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