# 1011 Dunbier Coupling Adjustment Bolt | Marine Trailer Part

🔧 Product Description

  

Dunbier Coupling Ball-Head Adjustment Bolt - Part Number: 1011

  

A replacement adjustment bolt for selected Dunbier standard and heavy-duty 50mm couplings. The bolt sets the internal ball-socket clearance, allowing normal tow-ball and coupling wear to be compensated within the manufacturer's adjustment range.

  

⚙️ Key Features

  

• Replacement threaded ball-head adjuster

• Restores correct coupling-to-ball clearance

• Suitable for selected fixed and override couplings

• Allows controlled adjustment without replacing a serviceable coupling body

• Includes only the components supplied in the current package

  

📏 Specifications

  

• Component type: Coupling adjustment bolt

• Thread and head profile must match the existing coupling

• Adjustment range is limited by coupling-body and socket wear

  

🔄 Cross Reference & Related Parts

  

• Dunbier: 1011

• Used with Dunbier 1010 standard coupling

• Used with Dunbier 1000 heavy-duty coupling

• Used with selected Dunbier 1041 and 1032 override couplings

• Comparable replacement: Coupling-specific coarse-thread adjustment bolt and nut with matching dimensions

  

🚤 Trailer Compatibility & Application

  

• Suitable only where the coupling body provides the matching threaded adjustment point

• Will not repair a cracked, stretched or severely worn ball socket

• Confirm the original thread before installation

  

🔌 Function

  

Sets the internal coupling socket clearance around the tow ball to reduce excessive play while allowing unrestricted articulation.

  

Common signs of wear or replacement:

  

• Bolt thread is stripped or seized

• Adjustment cannot remove excessive ball movement

• Lock nut repeatedly loosens

• Bolt head or contact end is deformed

• Coupling becomes tight in turns after incorrect adjustment

  

🛠️ Installation & Safety

  

• Clean and inspect the coupling before adjustment

• Connect the coupling to a correct unworn 50mm tow ball while setting clearance

• Tighten the lock nut after adjustment

• Check free articulation through the full towing angle

• Replace the complete coupling if safe adjustment cannot be achieved

  

📦 Condition

  

• Brand new Dunbier Marine Products trailer component

• Supplied as one coupling adjustment bolt assembly

• Supplied in original or equivalent packaging

## Details

- **Price:** 8.1 AUD
- **Vendor:** Dunbier
- **Tags:** Dunbier Boat Trailers | Marine Trailer Parts & Accessories

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 8.10 AUD | In stock |

## Images

- 1011 Dunbier Coupling Adjustment Bolt | Marine Trailer Part
- 1011 Dunbier Coupling Adjustment Bolt | Marine Trailer Part
- 1011 Dunbier Coupling Adjustment Bolt | Marine Trailer Part
- 1011 Dunbier Coupling Adjustment Bolt | Marine Trailer Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/1011-dunbier-coupling-adjustment-bolt)
> Updated: 2026-08-03