Lenco 12 x 12 inch Standard Trim Tab Kit + Double Rocker Switch 12V

The Lenco 12 by 12 inch Standard Mount Trim Tab Kit with Double Rocker Switch (model 15103-104) is the complete drop-in electric trim tab kit for boats in the 17 to 30 foot range. Two 12-gauge 304 stainless steel trim tab blades sized 12 inches long by 12 inches wide, two 12V Lenco ballscrew actuators (part 15054-001) with 6-foot pre-attached leads, two 20-foot actuator extension harnesses (part 30133-103), the Double Rocker switch kit, two upper mounting brackets with gland seal (15085-001), two lower mounting brackets (50014-001), and the stainless steel mounting hardware. One part number, complete install kit ready for the typical 17 to 30 foot recreational boat.

What trim tabs do for a boat. They control the running attitude of the hull at planing speed. Without trim tabs, the boat planes at whatever attitude the hull design and weight distribution dictate, which is usually bow-up enough to hurt visibility, fuel economy, and ride quality. With trim tabs, you adjust the bow attitude on the fly: deploy the tabs to push the bow down for cleaner planing attitude, retract for the natural attitude. Independent port and starboard control corrects list (one side sitting low) caused by uneven passenger weight, wind pressure, or water in the bilge. The result is smoother ride, drier ride, faster planing, better fuel economy, and the ability to put the bow exactly where you want it.

The Lenco ballscrew actuator is the design feature that separates these tabs from competing hydraulic-actuated systems. Hydraulic actuators use pressurized fluid in cylinders that eventually leak, corrode, and need expensive parts replacement. The Lenco ballscrew actuator uses an electric motor driving a precision ballscrew, fully sealed against water (rated submersible), no fluid to leak, and instant response: press the helm switch and the tab moves immediately, no lag for hydraulic pressure to build. The ballscrew design has been the marine standard for two decades because it just works longer with less maintenance.

The 12-gauge 304 stainless steel trim tab blades are the right specification for the recommended boat-length range. 304 grade gives long-term corrosion resistance in saltwater and freshwater. 12-gauge thickness is rigid enough to resist deflection at planing speeds while staying light enough to keep the actuator load reasonable. The 5/8-inch flared trailing edge improves water flow off the back of the tab. The 1/8-inch diameter hinge pin handles the cyclic load from tab actuation over years of use without wearing out.

The 12 by 12 inch tab size is sized for the 17 to 30 foot boat range. Both length and width are larger than the typical 9 by 9 or 9 by 12 tabs used on smaller boats, which gives more trim authority and better correction at the higher speeds typical of larger boats. For boats over 30 feet, Lenco makes 12 by 18 inch and larger tab kits with the same actuator and switch architecture.

Standard Mount geometry is the typical install configuration for boats with adequate transom height above the trim tab mount location. The actuator sits at the upper edge of the trim tab (above the tab when retracted, above the waterline when the boat is at rest). For boats with limited transom height where Standard Mount won't fit, Lenco's Edge Mount kit (different SKU) puts the actuator at the trailing edge of the tab and needs 4 inches less transom height. For most recreational boats with normal transom geometry, Standard Mount is the right choice and is the more cost-effective option.

The Double Rocker switch is the helm control. Two rocker switches at the helm: one for the port tab (rocker up to retract, rocker down to deploy), one for the starboard tab. Press both rockers down together to deploy both tabs simultaneously for bow-down attitude. Press one rocker down to deploy just that tab for list correction. Sealed keypad construction means the switch is fully waterproof and tactile (you can feel the rocker positions without looking).

The plug-and-play Deutsch connectors are the install convenience that makes this a real one-day install. Each actuator comes pre-attached to its 6-foot lead with the Deutsch connector already on the end. The 20-foot extension harnesses also have Deutsch connectors on both ends, so you can extend the actuator runs without cutting wires or crimping. Deutsch connectors are the marine-grade waterproof connectors used across the marine and automotive industries: snap together positively, seal against water, fully reversible.

The 20-foot extension harnesses are sized for typical install runs from the transom-mounted actuators to the helm-mounted control box. Most boats in the 17 to 30 foot range have transom-to-helm distances within the 26-foot total reach (6-foot lead plus 20-foot extension) the kit provides. For longer runs (large center consoles, sportfish boats), additional extensions are sold separately by Lenco.

Upper mounting brackets with gland seal are the install hardware that handles the actuator-to-transom connection. The gland seal prevents water intrusion at the bracket-to-transom mount point, which matters because that's where the wiring penetrates the transom. Lower mounting brackets handle the actuator-to-tab connection. Both bracket types are stainless steel for marine corrosion resistance.

Installation. Pick the tab mounting location on the transom (consult the install instructions for proper placement, typically on the bottom edge of the transom about a third of the way in from each chine). Bolt the tab to the transom with the included 5/16-inch stainless steel bolts and the supplied backing plates inside the transom. Mount the upper bracket with gland seal on the upper edge above the tab. Mount the lower bracket on the tab. Connect the actuator between upper and lower brackets. Plug the actuator leads into the 20-foot extension harnesses, route to the control box location below deck. Mount the Double Rocker switch at the helm. Connect 12V power. Total install time for an experienced installer is about 4 to 6 hours.

Fully submersible actuators are the durability spec that owners notice over years of use. The actuators sit at the bottom edge of the trim tab and get splashed and submerged whenever the boat is on plane. Cheaper actuators that aren't fully submersible eventually fail from internal corrosion. The Lenco actuators are sealed against immersion and are designed to live in the water for the lifetime of the boat.

What this isn't. It is not the LED Indicator switch variant (that's the Lenco kit with the helm-mounted LED tab position display, sold as a separate SKU at higher cost). It is not Edge Mount geometry (the Standard Mount in this kit needs 4 inches more transom height than Edge Mount). It is not a hydraulic trim tab kit. For boats in the 17 to 30 foot range with normal transom geometry that want a complete proven trim tab kit at reasonable cost, the 15103-104 is the right purchase.