1000 Dunbier H3325G Mackay Heavy-Duty Electric Coupling 3500kg | Marine Trailer Part

🔧 Product Description

Dunbier Heavy-Duty Standard Trailer Coupling 50mm - 3500kg - Part Number: 1000

A heavy-duty fixed 50mm ball coupling for unbraked or independently braked trailer applications up to its marked 3500kg rating. Although the supplied title describes an electric coupling, Dunbier and Mackay identify this component as a conventional manually operated heavy-duty coupling. The galvanised body provides practical corrosion resistance for boat-trailer service.

⚙️ Key Features

• Heavy-duty fixed coupling for a 50mm tow ball

• Galvanised finish for marine trailer corrosion protection

• Adjustable ball-head clearance using the optional coupling adjustment bolt

• Positive trigger and locking mechanism

• Manufactured as a rated trailer coupling for Australian road-trailer applications

📏 Specifications

• Coupling rating: 3500kg, subject to the stamped rating and complete trailer compliance

• Tow-ball size: 50mm

• Finish: Galvanised

• Coupling type: Fixed standard ball coupling

• Tow ball is not included

🔄 Cross Reference & Related Parts

• Dunbier: 1000

• Mackay: H3325G

• Adjustment bolt: Dunbier 1011

• Trigger replacement kit: Dunbier 1044C

• Suitable 50mm tow ball: Dunbier 1061 / Mackay H3354

• Comparable category: AL-KO, Ark and Trojan 50mm fixed couplings with the same verified rating and mounting pattern

🚤 Trailer Compatibility & Application

• Suitable for boat, box and general trailers using a fixed 50mm coupling

• The drawbar mounting pattern, bolt grade and coupling height must match the trailer

• The lowest rating among the coupling, tow ball, towbar and trailer remains the maximum legal capacity

🔌 Function

Clamps around the vehicle's 50mm tow ball to provide the primary articulated connection between the towing vehicle and trailer.

Common signs of wear or replacement:

• Excessive movement or knocking on the tow ball

• Trigger does not latch or release smoothly

• Cracks, distortion or elongated mounting holes

• Heavy corrosion around the ball socket or pivot

• Adjustment bolt no longer removes excessive clearance

🛠️ Installation & Safety

• Installation and rating verification should be completed by a competent trailer technician

• Use high-tensile fasteners of the correct size with suitable locking hardware

• Adjust the ball-head clearance without causing binding on the tow ball

• Always connect correctly rated safety chains independently of the coupling

• Inspect and lubricate the moving latch components as part of regular trailer servicing

📦 Condition

• Brand new Dunbier Marine Products trailer component

• Supplied as one complete 50mm heavy-duty coupling

• Supplied in original or equivalent packaging