Getting a Hygo exemption


Go to Hygo3 Exemption Guide

Coupling / Handbrake Mount


The coupling and handbrake lever are critical safety items, the mounting instructions below must be followed completely.


Installing a coupling to a trailer can seem like a simple task. Trailparts have a few tips and recommendations to ensure you and your load reach your destination safely. The Hygo3 coupling has the same hole mount pattern as standard 2500kg override couplings - 54mm x 184mm.

Positioning the coupling is important to the trailers structural integrity and connection strength. The coupling body must be positioned so that the likelihood of inadvertent damage to any component while in use is minimized. To meet compliance the positioning of the handbrake / breakaway lever in relation to the coupling is important. (see below)

Greasing / Lubrication

Properly greased couplings are the key to long life and safe use!

  • Tow ball connections should be greased because metal on metal causes screeching noises and premature wear. If the towball or inner coupling surface (tongue) wear becomes extreme the coupling can dislodge itself from the tow vehicle while in travel.
  • The coupling should be greased on the actuator load bearing surfaces using the grease nipples located on the coupling body regularly, depending on use.

Coupling mount torques;

  • Grade 8.8 M12 zinc plated bolts and locknuts. 75ft/lb 100Nm
  • Grade 10.9 M12 zinc plated bolts and locknuts. 90ft/lb 120Nm

Handbrake Mount Location


Important for Certification.


The cable guide, is only to be used if the minimum 12 degree angle can be maintained for correct hand brake operation. Failure to mount these parts correctly will void the warranty and violate the braking system certification as the break away cable may not function correctly when used.

The break away cable guide can be positioned either side of the coupling or mounted to the trailer drawbar to acheive the 12 degree angle. See the above diagram for the Trailparts reccomended mount position dimensions.

Lever Mount Plate

Trailparts have designed a reversible mounting bracket to suit the new Hygo 3 handbrake lever. This design can be customised or built in to your trailer plans.

Note: The hole positions are important for handbrake lever position and will ensure correct operation.

Apply for an Exemption / Certification

Download Brake Certificate

Present the trailer for testing at an NZTA approved entry certifier, who will issue a VIN number, a VIN plate, and affix it to the trailer. Alternatively (Trailparts recommended) you can apply for a WMI online then contact your Trailparts for a free VIN plate.

As a part of the VIRM (Vehicle Inspection Requirements Manual), the entry certifier will want to see copies of proof that the braking system fitted to the trailer is suitable for the load being carried. The below process with walk you though the exemption application including the one-off fee of $184 and a copy of the bank confirmation;

Account name: NZ Transport Agency
Bank: Westpac
Particulars: Last six digits of the vehicle’s VIN: XXXXXX
Code: CA11
Reference: Applicant Surname: XXXXXXXXXX

Email the below template to:

To whom it may concern,

See the attached exemption application for a trailer we have here that needs to get a WOF and be rated to 3500kg.

I’ve attached photos also showing the affixed VIN number, tyre size and the coupling for your reference also. Lastly, we have made the payment which is shown with the attached confirmation.

If you can please process this as soon as possible would be much appreciated.

Let me know any questions you may have.

Attach the follow documentation;

  • Copy of the bank confirmation ($184 fee)
  • Engineer's Statement with your own letter head (Sample)
  • Performance Equivalence Certificate (Notice of Conformity: Trailparts Supplied)
  • NZTA Exemption Application Form (CA11)
  • Photo evidence: Coupling info plate, VIN Plate, Tyre - showing size, Brake cable setup - emphasis on spring.


  • Approved entry certifiers are selected branches of the Automobile Association (AA), Vehicle Inspection NZ (VINZ), Vehicle Testing NZ (VTNZ), and Drivesure Vehicle Testing Ltd.
  • For manufacturers building a number of trailers, it is suggested that they apply for a WMI (World Manufacturer Identifier) that lets them issue their own VIN numbers. This will streamline the VIN application process, particularly in remote locations where no approved VIN issuer is present.