# 1680 Dunbier Axle Split Pins M4 x 25 Clamshell Pack | Marine Trailer Part

🔧 Product Description

  

Dunbier Zinc-Plated Axle Split Pins M4 × 25mm - Part Number: 1680

  

A clamshell-packed set of M4 × 25mm split pins for retaining the castellated axle nut on compatible Dunbier trailer stub axles. The pins provide a positive mechanical lock after wheel-bearing preload has been adjusted.

  

⚙️ Key Features

  

• Zinc-plated steel construction

• Sized for compatible Dunbier castellated axle nuts

• Single-use retaining hardware

• Clamshell-packed for workshop or onboard spares

• Suitable for wheel-bearing service and hub replacement

  

📏 Specifications

  

• Nominal size: M4 × 25mm

• Pack quantity: 10 split pins

• Finish: Zinc plated

• Application: Axle-nut retention

• Use only where the castellated-nut slot and spindle hole align correctly

  

🔄 Cross Reference & Related Parts

  

• Dunbier: 1680

• Axle nut, washer and split-pin service kits are available separately

• Select 25mm or 32mm length to match the spindle and castellated nut

  

🚤 Trailer Compatibility & Application

  

• Suits compatible Dunbier trailer axles and hubs using an M4 split pin

• Commonly used on standard, slimline and selected braked hub assemblies

• Confirm the hole diameter and required installed length before use

  

🔌 Function

  

Locks the castellated axle nut in its adjusted position so bearing preload cannot loosen during wheel rotation.

  

Common signs of wear or replacement:

  

• Old pin has been removed or straightened

• Pin is corroded, cracked or partly missing

• Axle nut slot cannot be secured safely

• Pin diameter is loose in the spindle hole

• Ends have broken during removal

  

🛠️ Installation & Safety

  

• Never reuse an axle split pin

• Set bearing preload before installing the pin

• Do not tighten the axle nut excessively just to align the slot; follow the hub service procedure

• Spread the legs securely around the nut

• Recheck hub end float and free rotation before fitting the dust cap

  

📦 Condition

  

• Genuine Dunbier Marine Products trailer component

• Brand new

• Supplied as one clamshell pack containing 10 split pins

• Supplied in original or equivalent packaging

## Details

- **Price:** 5.5 AUD
- **Vendor:** Dunbier
- **Tags:** Dunbier Boat Trailers | Marine Trailer Parts & Accessories

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 5.50 AUD | In stock |

## Images

- 1680 Dunbier Axle Split Pins M4 x 25 Clamshell Pack | Marine Trailer Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/1680-dunbier-axle-split-pins-m4-x-25-clam-pack)
> Updated: 2026-08-05