Boat Thruster Guide

What to buy, what it costs, what it takes to fit

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Discontinued thruster

Lewmar 185TT 3.0 Gen 1 (discontinued): specs, manual and parts

The Lewmar 185TT 3.0 Gen 1 is a tunnel thruster. The motor sits inside the boat and turns a propeller in a tube through the hull. Lewmar has replaced it with its Gen 2 range. Lewmar’s own 2018 thruster controls brochure, which we read on 11 October 2026, calls the units with the black control box the previous generation and the blue box system the next generation. Some dealers still list Gen 1 part numbers.

This page stays up for the owners still running one. It holds the published figures, the part numbers and the manual. You will not find the unit in the thruster finder, the tool here that matches a unit to your boat, or on the compare page. If you need a new thruster, start with either of those.

The published figures

The Lewmar 185TT 3.0 Gen 1 as Lewmar and the dealer listed it. Nothing here is our estimate.
TypeTunnel, fixed mount
Thrust128 lb (58 kgf)
As the maker printed it58 kgf / 128 lbs (Lewmar manual 500100, electric specification table)
Voltage12 V or 24 V
Motor3 kW
Tunnel diameter185 mm
Maker’s boat lengthNot published
Part number 59180112V59180224V
Last price we read No price held
Manual Lewmar’s manual for it

Service parts

These are Lewmar’s own part numbers for the parts an owner replaces, where we could find them: the pin that drives the propeller, the propeller, the anode, the brushes, the switch gear, the fuse and the motor. We read them on 11 October 2026. The last column says how we know each one fits this model. Give the dealer your thruster’s serial number from its label when you order.

Service parts for the Lewmar 185TT 3.0 Gen 1, with Lewmar’s part numbers.
Part Part number Lewmar’s name for it How we know it fits
Drive pin (shear pin) 559017 Drive pin Lewmar’s manual for this model
Propeller 589351 Propeller Lewmar’s manual for this model
Anode kit 589350 Anode Kit Lewmar’s manual for this model
Black box (the controller) 559003 Black Box Lewmar’s manual for this model
Solenoid (the motor switch)12 V unit B11126 Solenoid Lewmar’s manual for this model
Solenoid (the motor switch)24 V unit B11127 Solenoid Lewmar’s manual for this model
Main fuse12 V unit 589008 ANL fuse 250 A Lewmar’s manual for this modelFuse holder 589006 (589013 for the T2 holder).
Main fuse24 V unit 589007 ANL fuse 130 A Lewmar’s manual for this modelFuse holder 589006 (589013 for the T2 holder).
Tunnel gasket 553035 Tunnel gasket Lewmar’s manual for this model
Replacement motor12 V unit 583026 Motor Assembly Lewmar’s manual for this model
Replacement motor24 V unit 583027 Motor Assembly Lewmar’s manual for this model
Original Gen 1 control panels 589001, 589002, 589004 Touch panel, single joystick, double joystick (NOT 2.0 kW) Lewmar’s manual for this model
Gen 2 controls on a Gen 1 unit 589842 Black box convertor Lewmar’s 2018 controls brochureLewmar’s 2018 brochure: it lets a Gen 2 control panel run a black box thruster on the existing boat wiring.

What the manual and listings say

Lewmar's first-generation 185TT 3.0 tunnel thruster, the one wired through a black control box. It is rated 58 kgf (128 lb) on a 3.0 kW motor in a 185 mm tunnel. Lewmar's 2018 thruster controls brochure calls these the previous generation, replaced by its next-generation blue box system, the Gen 2 range sold today in the same motor sizes.

Lewmar sells a converter so a black box unit can take the newer controls.

Replacement and close alternatives

The replacement: Lewmar 185TT Gen 2, 3.0 kW. Lewmar’s Gen 2 range in the same motor size.

These are Lewmar’s nearest current sizes in the same line, by thrust.

Other makers’ current units of the same style, for the same end, within a quarter of its published thrust:

If you need a new one