35–70 HP Mercury Mariner Outboard Trim Tab Anode 31640Q04 – Zinc / Aluminium

Marine-grade aftermarket gearbox trim tab sacrificial anode for selected 35 HP, 40 HP, 45 HP, 50 HP, 60 HP and 70 HP Mercury / Mariner 2-stroke outboard engines.

Designed to help protect the gearbox and lower unit against galvanic corrosion while providing a trim tab for steering torque adjustment.

Main Part Number: 31640Q04

Available in Zinc or Aluminium.

Choose Your Anode Material

Zinc Anode

• Traditional sacrificial anode material

• Particularly suitable for saltwater applications

Aluminium Anode

• Marine-grade aluminium alloy

• Suitable for saltwater and brackish water applications

• Lightweight alternative to zinc

Please follow the engine manufacturer's recommendations when selecting anode material.

Fitment – Mercury / Mariner Outboards

2-Stroke Models

Suitable for selected:

• 35 HP – 2-Stroke

• 40 HP – 2-Stroke

• 45 HP – 2-Stroke

• 50 HP – 2-Stroke

• 60 HP – 2-Stroke

• 70 HP – 2-Stroke

Important Fitment Notes

Mercury and Mariner used different gearbox and trim tab designs across engine generations.

Compatibility depends on:

• Engine model and horsepower

• Engine production year

• Engine serial number

• Gearbox configuration

• Original trim tab part number

Not suitable for all Mercury / Mariner engines within the listed horsepower range.

Please confirm the original part number and trim tab design before ordering.

Replaces Mercury / Mariner Part Numbers

Main Reference

• 31640Q04

Additional References Supplied

• 316404

• 316406

• 31640A4

• 31640B4

• 31640Q03

• 31640Q4

• 97-31640Q4

• 97-31640T4

• 97-31640T6

• 97-8M0059338

The references above are supplied as cross-reference information. Confirm compatibility with the relevant Mercury parts diagram where necessary.

OEM part numbers are used for identification and compatibility reference only.

Product Details

• Product Type: Gearbox Trim Tab Anode

• Material: Zinc or Aluminium

• Application: Mercury / Mariner Outboards

• Horsepower: 35, 40, 45, 50, 60 and 70 HP

• Engine Type: 2-Stroke

• Location: Gearbox / Lower Unit

• Purpose: Sacrificial corrosion protection

• Additional Function: Steering torque adjustment

• Quality: Marine-grade aftermarket replacement

• Quantity: 1 anode

Package Includes

1 × Gearbox Trim Tab Anode

Supplied in your selected material:

• Zinc

• Aluminium

Mounting hardware is not included unless otherwise specified.

Important Compatibility Information

Before ordering, please check:

• Exact Mercury / Mariner engine model

• Engine horsepower

• Engine production year and serial number

• Gearbox configuration

• Original trim tab part number

• Existing anode shape and dimensions

• Required anode material

If the part looks the same as yours, this does not always mean it is the correct part for your outboard.

If unsure, please contact SSI Marine with your engine model and serial number for assistance.

Why Buy From SSI Marine?

• Workshop-tested aftermarket & OEM-spec parts

• Same-day dispatch before 1 PM Monday–Friday

• Royal Mail Tracked 24

• UK stock – collection available from Leigh, Greater Manchester

• Technical support from experienced outboard specialists

Buyer Responsibility

Please confirm compatibility with your exact Mercury / Mariner engine model, serial number and gearbox configuration before purchase.