Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Enjoy free shipping during the holidays! Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.

Enjoy Our Extended FREE RETURNS

We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later). We'll even cover the cost of return shipping. Learn more about our Return Policy.

Shopping Cart
Questions & Answers

Product Discontinued by Manufacturer

Garmin Reactor 40, Mechanical Retrofit has been discontinued by Garmin and is no longer available. Our product experts have helped us select these available replacements below.You can also explore other items in the Boating & Marine, Marine Electrical yourself to try and find the perfect replacement for you!

Product Info for Garmin Reactor 40, Mechanical Retrofit

Our Most Responsive Autopilot System on the Waterimage

Solid-state 9-axis Attitude Heading Reference System (AHRS)

Minimizes heading error, course deviation, rudder movement and power consumption while providing a comfortable ride

Minimal commissioning and calibration

Supports heading hold, wind hold, step turns and tack/jibe modes

With a complete package designed for powerboats and sailboats, Garmin brings an advanced marine technology to the boating public that was once only available for commercial boats. The Reactor 40 autopilot series is simply the most responsive autopilot system we have ever offered.

Reactor 40 autopilots are very versatile. Both powerboat and sailing features are available in all corepacks, including heading hold, wind hold, tack/jibe, step turns and more; simply pick the autopilot thats compatible with your existing steering system. If you dont see a compatible Reactor 40, youll find the Reactor 40 mechanical/retrofit/solenoid is compatible with a wide variety of steering systems, whether hydraulic, cable drive, mechanical and solenoid. Just pair GRF 10 with your drive system already on board.

The Reactor 40 mechanical/retrofit/solenoid autopilot corepack is ideal for sailboats and powerboats with direct or cable-actuated steering systems. This Reactor 40 below-deck autopilot system gives captains that extra set of hands they need so you can safely attend to your sails, lines, winches and radios, without worry. With its solid-state 9-axis AHRS, Reactor 40 mounts anywhere, in any orientation and requires minimal commissioning.

Solid-state 9-axis AHRS

With its advanced solid-state 9-axis AHRS, you can mount Reactor 40 nearly anywhere, in any orientation. In addition, this new system greatly minimizes heading error, course deviation, rudder movement and power consumption while providing a comfortable ride for all on board.

Reacts to Conditions

This amazing autopilot actually reacts to the sea to hold your course. Even when the boat is pitching and rolling, you can remain confident that the Reactor 40 autopilot will keep you on your desired course.

Minimal Commissioning and Calibration

All autopilots require commissioning and calibration all of them. We know you just want to get on the water, so we made this process as fast and easy as possible. Thats the power of simple.

Full Integration with Garmin Chartplotters

Combined with a compatible Garmin networked chartplotter, you can have full control of Reactor 40 from wherever you are on the boat. In addition to holding its course in virtually all weather and wind conditions, the system can smoothly perform a variety of preprogrammed trolling and search procedures. Plus, with a compatible Garmin networked chartplotter and BlueChart g2 Vision charts (sold separately), you gain optional features such as Auto Guidance, which automatically steers GPS paths.

Stay in Control with Shadow Drive Technology

On hydraulic installations, the Reactor 40 mechanical/retrofit/solenoid autopilot corepack can add optional patented Shadow Drive technology. This gives you the security of knowing you maintain control, even when the autopilot is engaged. The Shadow Drive system automatically disengages the autopilot if the helm is turned, giving you the freedom to maneuver the boat. The autopilot automatically re-engages when you hold a steady course.

Choose from 3 Class Drives

Reactor 40 is available with 3 linear drives (sold separately) capable of driving many different steering systems on most midsize to large vessels (depending on the particular installation). All Garmin linear drives include built-in rudder feedback sensing.

Class A Drive Unit up to 28,500 lbs of displacement

Class B Compact Drive Unit up to 48,400 lbs of displacement

Class B Drive Unit up to 79,000 lbs of displacement

Connect to Networked Devices

The Reactor 40 autopilot is operated using up to 3 GHC helm control units. GHC communicates with the autopilot system via your NMEA 2000 network, so autopilot heading data can be shared easily with other devices. This enables MARPA and chart overlay when connected to a Garmin chartplotter. An optional handheld wireless remote control is also available; however, for the highest level of convenience, control GHC using a compatible quatix 3 or quatix 5 marine multisport smartwatch.

Add Even More Peace of Mind

Add an optional GRF 10 rudder feedback sensor, and you can further enhance the performance of your Reactor 40 autopilot.

Features of Garmin Reactor 40, Mechanical Retrofit

  • CCU dimensions: 4.3 " x 4.4 " x 1.9 " (10.9 x 11.2 x 4.8 cm)
  • ECU dimensions: 6.6 " x 4.6 " x 2.1 " (16.8 x 11.7 x 5.3 cm)
  • Supply voltage: 10 V to 30 V
  • Operating temperature: -15 C to 60 C (5 F to 140 F)
  • Maximum sustained motor current: 15A
  • Maximum instantaneous motor current: 40A
  • Maximum clutch current: 2.5A (for drives requiring higher current than 2.5A, a relay needs to be added to the clutch circuit)
  • Buzzer/Alarm Specifications
  • Dimensions (L Diameter): 29/32 in. 1 in. (23 mm 25 mm)
  • Weight: 2.4 oz. (68 g)
  • Temperature range: from 5F to 131F (from -15C to 55C)
  • Cable length: 10 ft. (3.0 m)

Package Contents:

  • Garmin Reactor 40, Mechanical Retrofit
  • Reactor 40 CCU (Course Computer Unit)
  • GHC 20 helm control display
  • ECU (Electronic Control Unit)
  • ECU power cable
  • Interconnect cable
  • Buzzer
  • NMEA 2000 drop cables (2 meters)
  • NMEA 2000 T-connectors
  • Male and female terminators
  • Documentation

Related Products to Garmin Reactor 40, Mechanical Retrofit

Garmin Reactor 40, Mechanical Retrofit Unavailable & Discontinued Models

List of Unorderable Models

  • Garmin Reactor 40, Mechanical Retrofit Corepack, 010-00705-49 , MPN: 010-00705-49 , UPC: 753759189396 , Code: GA-F75-GARR40MRC-010-00705-49
Compare (0)