Service and repair mechanical transmission assemblies on land-based equipment

This standard covers the service and repair of mechanical transmission assemblies on land-based equipment. It includes the removal, dismantling, repairing and reassembly of gearboxes, transmissions and their component parts (e.g. sliding mesh, constant mesh, synchromesh), the testing, diagnosis and repair practices required for both simple and complex transmissions, as well as the transmission components necessary to transmit power to drive wheels and moving machinery parts, (e.g. rear axle assemblies, front axle assemblies or drive-shaft assemblies).

When working with machinery or equipment you should be trained and hold current certification, where required, in accordance with the relevant legislation.

When working on high voltage (hazardous voltage/HaV) electric vehicles, de-energising must be done by a person who has been trained in accordance with the manufacturer’s procedures.

This standard is for those who work in land-based engineering under supervision.

1. be aware of hazards and assess the risks associated with the activity and the location where it is to be carried out
2. be aware of the potential environmental impact associated with the activity and the ways in which this can be controlled
3. select and wear suitable clothing and personal protective equipment (PPE)
4. select, prepare, use, maintain, and store the tools and equipment required to carry out the activity in accordance with the relevant legal requirements, manufacturer's instructions and company practices
5. check that the land-based equipment requiring service and repair is safe, prepared and isolated from power sources, where required
6. take the necessary precautions to prevent the escape of chemicals, gases and other substances and minimise dangers from contamination and hazards, where required
7. use a variety of methods to collect diagnostic information to identify defects and faults  
8. determine the requirements for service and repair
9. evaluate the serviceability of transmission parts in a repair
10. identify and establish the availability of replacement components required for the activity
11. remove and replace mechanical transmission assemblies and their related components from land-based equipment
12. remove contamination from a failed transmission
13. dismantle, service/repair and reinstate mechanical transmission assemblies and their components in line with the manufacturer’s specification and standards
14. remove and replace worn and damaged components in accordance with instructions and specifications
15. confirm that equipment is correctly set or calibrated following service and repair
16. use suitable testing methods to assess the performance of the reassembled system on completion of the activity and confirm that it performs to operating specifications prior to returning the equipment to the customer
17. recycle or sustainably dispose of the different types of waste, including hazardous and non-hazardous, caused by the activity, in accordance with the relevant legal and environmental requirements and company policy
18. complete records as required by the relevant legislation, warranty requirements and company procedures

1. how to identify hazards and assess risks when preparing to service and repair land-based equipment 
2. the type of clothing and personal protective equipment (PPE) suitable for the activity
3. the tools and equipment required to carry out the activity and how to select, prepare, use, maintain and store these safely and correctly, in accordance with the manufacturer's instructions and company practices
4. the relevant legal requirements for the preparation and use of work equipment
5. how land-based equipment should be prepared for service and repair
6. the dangers created by stored energy and how to respond to these during the preparation stage 
7. the hazardous chemicals, gases and other substances that may be present and how they should be dealt with 
8. the different methods that can be used for the assessment of defects and faults with mechanical transmission assemblies and for the identification of the root cause  
9. the typical defects and faults that occur with mechanical transmission assemblies on land-based equipment 
10. the factors that determine whether it is worthwhile carrying out the service and repair, such as cost, estimated working life or urgent need for the equipment
11. the components required for the service and repair and the company procedures for obtaining replacements 
12. how to evaluate the serviceability of transmission parts in a repair
13. the types, construction, and operating principles of gearboxes and their components
14. how to remove and replace mechanical transmission assemblies and their components from land-based equipment
15. how to remove contamination from a failed transmission
16. how to dismantle, service/repair and reinstate mechanical transmission assemblies and their components in line with the manufacturer’s specification and standards
17. how to follow the drive path through mechanical transmission assemblies and their components using the manufacturer’s schematic drawings
18. the types, construction and operating principles of powered front and rear axles and their components
19. the relationship between power, speed and torque, including the relationship to the transmission layout, siting of brakes and the size of components
20. the methods of setting equipment and machinery following service and repair 
21. the methods of testing mechanical transmission assemblies on completion of the activity to confirm that that they perform to operating specifications prior to returning the equipment to the customer
22. how to recycle or sustainably dispose of the different types of waste, including hazardous and non-hazardous, caused by the activity, in accordance with the relevant legal and environmental requirements and company policy 
23. the potential impact that the activity could have on the environment and the ways in which this can be controlled
24. the information that needs to be recorded, the company procedure for maintaining records and the requirements of data protection legislation

Carry out the required activities for a minimum of three separate transmission assemblies and components: one of which must be a complex mechanical gearbox on a land-based vehicle:

gearboxes and their components e.g:

1. sliding mesh

2. constant mesh

3. synchromesh

4. range and reduction boxes

5. forward and reverse shuttle

6. PTO drives

7. robotic/hydraulically shifted range boxes

front and rear axles and their components e.g:

1. front and rear axle reduction units

2. differentials

3. differential locks

4. half shafts

5. constant velocity joints

6. universal joints

Hazardous chemicals and substances could include:

• fuels

• oils

• fluids

• gases

• dust

• compressed air

Instructions and specifications:

• drawings/plans

• schedules

• method statements

• Standard Operating Procedures (SOPs)

• manufacturer’s instructions

• customer requirements

• verbal instructions

Methods of diagnosis:

• visual inspections

• functional and operational tests

• diagnostic equipment

• remote electronic control and monitoring systems

• reviewing technical data

Stored energy:

• springs

• belt tension

• hydraulic pressure

• electrical discharge

• accumulator discharge