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Demonstrate knowledge of tractor and agricultural machinery tyres and wheels

Level / 3
Credits / 4

PurposeThis theory-based unit standard is for people in the agriculturalmachinery repair industry. People credited with this unit standard are able to demonstrate knowledge of: tractor and agricultural machinery tyre types and sizes; tyre damage, repair techniques and maintenancerequirements; and tractor and agricultural machinery wheels.

Subfield / Motor Industry
Domain / Tyres
Status / Registered
Status date / 25 January 2008
Date version published / 25 January 2008
Planned review date / 31 December 2012
Entry information / Open.
Replacement information / This unit standard and unit standard 24460 replaced unit standard 5440.
Accreditation / Evaluation of documentation and visit by NZQA and industry.
Standard setting body (SSB) / NZ Motor Industry Training Organisation (Incorporated)
Accreditation and Moderation Action Plan (AMAP) reference / 0014

This AMAP can be accessed at

Special notes

1Legislation relevant to this unit standard includes but is not limited to – Land Transport Rule: Tyres and Wheels 2001, Rule 32013.

2Land Transport Rules are produced for the Minister of Transport by Land Transport New Zealand. These rules are available online at

3Definition

Agricultural machinery refers to any machine or equipment used in maintenance, harvesting and cultivation on farms. These include but are not limited to – tractors, ploughs and tillers, graders, post rammers, weed control implements, hay mowers, hay balers, feed-out wagons, harvesters, combine harvesters.

Elements and performance criteria

Element 1

Demonstrate knowledge of tractor and agricultural machinery tyre types and sizes.

Performance criteria

1.1Tyre patterns are described, and applicable use identified for each type, in accordance with tyre manufacturer specifications.

Rangeincludes but is not limited to – basic lug pattern (directional, angle of lugs, length of lug to centre line, industrial lug), grass or turf pattern, flotation and soil compaction, front non-driving tyres (tri-rib, broken tri-rib, multi-rib).

1.2Tyre sizes are defined in accordance with tyre manufacturer specifications.

Rangeincludes but is not limited to – measurement relating to rim diameter and tyre section width, low profile aspect ratio, side wall markings (speed and loading indexing characteristics).

1.3Tyre construction is described in accordance with tyre manufacturer specifications.

Rangeincludes but is not limited to – cross ply (rayon and nylon); radial (rayon and nylon); steel belted plies; beads, side walls, apexes and chafers; rubber compounds.

1.4Dynamic rolling circumference is described in accordance with tyre manufacturer specifications.

Rangeincludes but is not limited to – matching tyre circumferences for four-wheel drive and wheel assisted machines, front tyre lead (performance, safe handling, mechanical considerations of the machine).

1.5Tyre valve types are described in accordance with tyre manufacturer specifications.

Rangeincludes but is not limited to – water valves, dry valves, tubeless stems, tube stems.

Element 2

Demonstrate knowledge of tyre damage, repair techniques, and maintenance requirements.

Performance criteria

2.1Tyre wear is described in accordance with tyre or machine manufacturer descriptions.

Rangeincludes but is not limited to – under-inflation wear pattern, over-inflation wear pattern.

2.2Tyre rupture is identified in accordance with tyre manufacturer description.

Rangeincludes but is not limited to – broken tyre walls, lug damage through spinning, staking, ozone cracking, petroleum and herbicide deterioration.

2.3Tyre repair methods are described in accordance with tyre manufacturer recommendations.

Rangeincludes but is not limited to – permanent vulcanising, cold chemical cure, temporary boots, tyre ‘worms’.

2.4Tyre maintenance criteria are described in accordance with tyre manufacturer recommendations.

Rangeincludes but is not limited to – pressures, hard surface, soft surface, ballast, anti-freeze, water, calcium chloride, petroleum product and herbicide contamination, deterioration prevention.

Element 3

Demonstrate knowledge of tractor and agricultural machinery wheels.

Performance criteria

3.1Rim and wheel disc configurations are described in accordance with machine manufacturer specifications.

Rangeincludes but is not limited to – single well rims, dual rims, wheel discs and settings, power adjusted rims.

Please note

Providers must be accredited by NZQA, or an inter-institutional body with delegated authority for quality assurance, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.

Industry Training Organisations must be accredited by NZQA before they can register credits from assessment against unit standards.

Accredited providers and Industry Training Organisations assessing against unit standards must engage with the moderation system that applies to those standards.

Accreditation requirements and an outline of the moderation system that applies to this standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The AMAP also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.

Comments on this unit standard

Please contact the NZ Motor Industry Training Organisation (Incorporated) if you wish to suggest changes to the content of this unit standard.

 New Zealand Qualifications Authority 2018