Diagnose and rectify lift truck transmission and driveline system faults

Business Sectors (Suites): Maintenance and Repair - Lift Truck
Developed by: IMI
Approved on: 31 Jan 2022


This standard is about diagnosing and rectifying faults occurring within lift truck gearboxes (hydrostatic, automatic or powershift types), hubs and bearings, driveline shafts, differentials and final drive units.

Performance criteria

You must be able to:

P1 wear suitable personal protective equipment throughout all diagnostic methods and rectification activities
P2 support the identification of faults, by reviewing lift truck:

P2.1 technical data

P2.2 diagnostic test procedures
P3 prepare, connect and test all the required equipment following manufacturers' instructions prior to use
P4 use diagnostic methods which are relevant to the symptoms presented
P5 collect diagnostic information in a systematic way relevant to the diagnostic methods used
P6 collect sufficient diagnostic information to enable an accurate diagnosis of transmission and driveline system faults
P7 accurately identify and record any system deviation from acceptable limits 
P8 ensure your assessment of dismantled sub-assemblies, components and units accurately identifies their condition and suitability for repair or replacement
P9 promptly inform the relevant person(s) where repairs are uneconomic or unsatisfactory to perform
P10 use the equipment required correctly and safely throughout all rectification activities
P11 carry out all rectification activities following:

P11.1 manufacturers' instructions
P11.2 your workplace procedures
P11.3 health and safety requirements.
P12 work in a way which minimises the risk of :

P12.1 damage to other lift truck systems, units and components
P12.2 damage to your working environment
P12.3 injury to yourself and others
P12.4 contact with hazardous substances
P12.5 instability when working on the lift truck
P13 ensure all repaired and replaced  components and units conform to the lift truck operations specification and any legal requirements
P14 adjust components and units correctly to ensure that they operate to meet system requirements, when necessary
P15 promptly record and report any additional faults you notice during the course of work 
P16 use testing methods which are suitable for assessing the performance of the system rectified
P17 ensure the transmission and driveline system rectified performs to the lift truck operating specification and any legal requirements prior to return to the customer
P18 ensure your records are accurate, complete and promptly passed to the relevant person(s) in the format required
P19 complete all system diagnostic activities within the agreed timescale
P20 promptly report any anticipated delays in completion to the relevant person(s) in authority 

Knowledge and Understanding

You need to know and understand:

Legislative and organisational requirements and procedures
K1 the health and safety legislation and workplace procedures relevant to diagnosing and rectifying driveline faults including PPE
K2 legal requirements relating to the lift truck
K3 your workplace procedures for:

K3.1 recording fault location and correction activities
K3.2 reporting the results of tests

K3.3 the referral of problems
K3.4 reporting delays to the completion of work
K4 the importance of working to recognised diagnostic procedures and processes and obtaining the correct information for diagnostic activities to proceed
K5 the importance  and purpose of  recording diagnostic and rectification activities
K6 the importance of working to agreed timescales and keeping others informed of progress
K7 the relationship between time, costs and profitability
K8 the importance of promptly reporting anticipated delays to the relevant person(s) in authority 

Electrical and electronic principles
K9 electrical and electronic principles associated with transmission and driveline systems, including types of sensors and actuators, their application and operation
K10 how electrical and electronic transmission and driveline systems operate, including electrical component function, electrical inputs, outputs, voltages and oscilloscope patterns, digital and fibre optics principles
K11 the interaction between electrical, electronic and mechanical components within lift truck transmission and driveline systems
K12 how transmission and driveline electrical systems interlink and interact, including multiplexing
K13 electric, units, terms and schematics
K14 electrical safety procedures

Use of diagnostic and rectification equipment
K15 how to prepare and test the accuracy of diagnostic testing equipment *

K16 how to use diagnostic and rectification *equipment for transmission and driveline mechanical, electrical, hydraulic and fluid systems, specialist repair tools and general workshop equipment

Transmission and driveline faults, their diagnosis and correction
K17 how transmission and driveline mechanical, electrical, electronic and hydraulic and fluid systems are constructed, dismantled, reassembled and operate
K18 the types and causes of transmission and driveline mechanical, electrical, electronic and hydraulic and fluid system, component and unit faults and failures
K19 transmission and driveline mechanical, electrical and hydraulic and fluid component and unit replacement procedures, the circumstances which will necessitate replacement and other possible courses of action
K20 how to find, interpret and use sources of information on transmission and driveline electrical operating specifications, diagnostic test procedures, repair procedures and legal requirements
K21 lift truck operating specifications for limits, fits and tolerances relating to transmission and driveline mechanical, electrical, electronic and hydraulic and fluid systems for the lift truck(s) on which you work
K22 how to select the most appropriate diagnostic testing method for the symptoms presented
K23 how to carry out systematic diagnostic testing of transmission and driveline mechanical, electrical and electronic, hydraulic and fluid systems using a prescribed process or format
K24 how to assess the condition evident within transmission and driveline mechanical, electrical, electronic, hydraulic and fluid components and units 
K25 how to interpret test results and lift truck data in order to identify the location and cause of lift truck system faults
K26 how to carry out rectification activities in order to correct faults in the transmission and driveline mechanical, electrical, electronic and hydraulic and fluid systems
K27 the relationship between test methodology and the faults repaired – the use of appropriate testing methods
K28 how to make cost effective recommendations for rectification


1. **Transmission and driveline systems** include:

1.1. gearbox
1.2. hubs and bearing 
1.3. driveline shafts
1.4. torque converter
1.5. final drive assembly

2. Diagnostic methods include: 

2.1. measurements
2.2. functional testing
2.3. pressure
2.4. electrical and electronic systems testing

3. Equipment includes: 

3.1. diagnostic and rectification equipment for transmission
3.2. mechanical systems
3.3. diagnostic and rectification equipment for transmission electrical systems 
3.4. diagnostic and rectification equipment for transmission hydraulic and fluid systems 
3.5. specialist repair tools
3.6. general workshop equipment 

4. Faults can be:

4.1. mechanical

4.2. electrical and electronic
4.3. hydraulic and fluid

Scope Performance

Scope Knowledge





​This section contains examples and explanations of some of the terms used but does not form part of the standard.

Diagnostic Testing
**Defined as:

a. verify the fault
b. collect further information 
c. evaluate the evidence 
d. carry out further tests in a logical sequence
e. rectify the problem
f. check all systems 

Rectification activities
A suitable repair or replacement that rectifies the fault(s) identified from the diagnostic activites carried out. 

Links To Other NOS

External Links

Version Number


Indicative Review Date

31 Jan 2025





Originating Organisation


Original URN


Relevant Occupations

Lift Truck Service Technician (Automotive), Lift Truck Trailer Diagnostic Technician (Automotive), Lift Truck Trailer Master Technician (Automotive), Lift Truck Workshop Controller

SOC Code



Diagnose; rectify; lift truck; transmission; driveline; system; faults;