Block E – Drive Train

Trends

More drive train components are now electronically‐controlled requiring truck and transport mechanics to have more specialized training and the ability to use diagnostic software.

Components are being designed to handle higher torque loads and ratings.

The use of synthetic oils has resulted in extended service intervals and component life.

There is an increased use in hybrid drive systems as the industry continues to move toward environmentally sustainable practices.

Related Components (including, but not limited to)

Clutches: discs, center plates, release springs, bearings, pressure plates.

Transmissions: seals, gaskets, gears, bearings, breathers, filters, oil pumps, splined shafts, connectors, torque converters, coolers, valve bodies, clutch packs, wiring, solenoids, ECMs, shift bar housings, shift lever, knob, air lines, cylinders, gauges, sensors.

Driveline systems: driveshaft, u-joint, yokes, slip-joints, seals, steady bearings, support brackets, grease fittings.

Differentials: seals, breathers, axles, gaskets, hubs, gears, planetaries, bearings, shift forks, filters, coolers, power dividers, locking devices, sensors, wiring.

Transfer cases: shifter, differential, clutches, gears, gaskets, seals, bearing, breathers, spline shafts, sensors.

Tools and Equipment

ASee Appendix A.

Task 20 Services, diagnoses and repairs clutches.

Context

The clutch transfers energy and provides a means of disconnect from the engine to the transmission.

Truck and transport mechanics must diagnose, service and repair the clutch to increase longevity and optimal performance of the vehicle.

Servicing includes lubrication and adjustment of components as well as routine maintenance.

Required Knowledge

• K 1 types of clutches such as pull, push, self-adjusting and manual adjusting
• K 2 clutch components such as discs, center plate, release springs and release bearings
• K 3 clutch controls such as cable, linkage and hydraulic
• K 4 clutch operation and adjustment
• K 5 clutch operation components such as hydraulic-assisted, air-assisted and electronically controlled
• K 6 conditions that indicate that clutch needs servicing such as hard shifting, loss of pedal free play and excessive pedal free play
• K 7 clutch faults such as shock loads, worn parts, seized release bearings and broken clutch springs

Sub-task - E-20.01 Services clutches.

Key Competencies

• E-20.01.01 lubricate cross shafts, linkages and release bearings
• E-20.01.02 adjust clutch and linkages to obtain manufacturer’s tolerance between release bearing and clutch brake
• E-20.01.03 inspect master and slave cylinders for leaks and damage
• E-20.01.04 inspect and adjust cables, linkages and clutch brakes to ensure efficient operation

Sub-task - E-20.02 Diagnoses clutches.

Key Competencies

• E-20.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-20.02.02 perform sensory inspections such as pedal feel and observing burnt clutch material, and worn or broken components to confirm complaint and establish a preliminary diagnosis
• E-20.02.03 inspect master and slave cylinder for leaks and damage
• E-20.02.04 use diagnostic tools such as feeler gauges, spring gauges and other measuring devices
• E-20.02.05 compare results to manufacturers’ specifications or expected values to verify diagnosis
• E-20.02.06 perform failure analysis to determine root cause of failure

Sub-task - E-20.03 Repairs clutches.

Key Competencies

• E-20.03.01 remove and replace worn, damaged or faulty components such as linkages, cross shafts, bushings, clutch brakes, clutch and pressure plate
• E-20.03.02 ensure flywheels reconditioned according to manufacturers’ specifications
• E-20.03.03 ensure proper alignment of discs and pressure plates
• E-20.03.04 adjust clutch and linkages to obtain manufacturer’s tolerance between release bearing and clutch brake
• E-20.03.05 bleed air from master and slave cylinders
• E-20.03.06 verify repair using methods such as road testing and sensory observations
• E-20.03.07 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 21 Services, diagnoses and repairs manual transmissions and transfer cases.

Context

The transmission of a vehicle transfers power from the engine through the drive shaft to the wheels to enable movement of the vehicle. The transmission allows for selection of gear ratios needed for various loads and speed conditions. The transfer case allows transmission power to be directed to components such as additional axles and/or accessories.

Truck and transport mechanics diagnose, service and repair transmission and transfer cases minimizing down time of the vehicle and ensuring the safety of the vehicle, driver and public. Servicing includes routine maintenance.

Required Knowledge

• K 1 types of manual transmissions such as 10-, 13-, 15- and 18-speed, double countershaft and triple countershaft
• K 2 manual transmission components such as seals, gaskets, gears and bearings
• K 3 auxiliary shift components such as slave cylinder, air lines, regulators and shift knobs
• K 4 types of transfer case and transfer case shift controls such as air, electrical and mechanical
• K 5 common component faults such as missing teeth in gears, lack of lubrication and worn synchronizers

Sub-task - E-21.01 Services manual transmissions and transfer cases.

Key Competencies

• E-21.01.01 clean components such as breathers and transmission cases for inspection
• E-21.01.02 remove and replace oil according manufacturers’ specifications and employer maintenance schedule
• E-21.01.03 inspect slave cylinders, range valves, air lines and seals for leakage
• E-21.01.04 record service information and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - E-21.02 Diagnoses manual transmissions and transfer cases.

Key Competencies

• E-21.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-21.02.02 perform diagnostic procedure by following troubleshooting tree or schematic supplied by manufacturer to confirm complaint
• E-21.02.03 compare test results to manufacturers’ specifications or expected values in order to assess components for wear, damage or defects
• E-21.02.04 perform failure analysis to determine root cause of failure
• E-21.02.05 record test results and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - E-21.03 Repairs manual transmissions and transfer cases.

Key Competencies

• E-21.03.01 remove and replace worn, damaged or faulty components such as slave cylinders, range valves, lines, cases, seals, gears and synchronizers
• E-21.03.02 rebuild components such as transmissions and transfer cases by replacing worn or broken parts according to manufacturers’ specifications
• E-21.03.03 repair or replace components such as synchronizers, bearings, main shafts, and counter shafts according to manufacturers’ specifications
• E-21.03.04 time gears and adjust bearing pre-loads to ensure proper operation of component/equipment
• E-21.03.05 install power take-offs (PTOs) and ensure gear backlash is adjusted according to manufacturers’ specifications
• E-21.03.06 verify repair using methods such as road testing or sensory observations
• E-21.03.07 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 22 Services, diagnoses and repairs automatic transmissions.

Context

Truck and transport mechanics must have a good understanding of automatic transmission operation and components in order to service, diagnose and repair, ensure proper function and reduce downtime.

Required Knowledge

• K 1 automatic transmission components such as torque converters, valve bodies, pumps, solenoids and clutches
• K 2 failures of components such as gears, bearings and clutch packs
• K 3 hybrid transmissions
• K 4 types and locations of coolers
• K 5 servicing procedures for components such as clutch packs, bearings, seals, torque converters, bands, one-way clutches, servos and planetaries
• K 6 diagnostic codes, troubleshooting trees and schematics
• K 7 pressure loss, solenoid and valve failures
• K 8 testing procedures for automatic transmissions such as stall testing and pressure readings

Sub-task - E-22.01 Services automatic transmissions.

Key Competencies

• E-22.01.01 perform sensory inspections of components to identify leaks
• E-22.01.02 check and perform software updates following manufacturers’ recommended procedures
• E-22.01.03 remove and replace consumable components such as oil and filters according manufacturers’ specifications and employer maintenance schedule
• E-22.01.04 recycle and/or dispose of consumable components according to jurisdictional regulations

Sub-task - E-22.02 Diagnoses automatic transmissions.

Key Competencies

• E-22.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-22.02.02 check for external leaks and oil condition
• E-22.02.03 perform diagnostic procedure by following troubleshooting tree or schematic supplied by manufacturer to determine failure
• E-22.02.04 perform road test to assess components for wear, damage or defects using diagnostic tools such as pressure gauges, computers or other specialized equipment provided by the manufacturer
• E-22.02.05 interpret fault codes and test results to ensure operation is within manufacturers’ specifications
• E-22.02.06 record test results and inspection findings according to manufacturers’ requirements for warranty

Sub-task - E-22.03 Repairs automatic transmissions.

Key Competencies

• E-22.03.01 remove and replace worn, damaged or faulty components such as solenoids, valves, sensors, hoses, lines and wiring harnesses
• E-22.03.02 confirm most current version of software is installed in the ECM
• E-22.03.03 rebuild transmission to manufacturers’ specifications
• E-22.03.04 repair transmission by replacing internal components (torque converters, pumps and valve bodies) and external components (oil coolers) according to manufacturers’ specifications
• E-22.03.05 ensure road test is performed to verify repair operates to manufacturers’ specifications
• E-22.03.06 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 23 Services, diagnoses and repairs automated transmission.

Context

The automated transmission is a standard transmission shifted automatically using computer controlled actuators and may have a clutch pedal and electronic gear selector.

Required Knowledge

• K 1 manual transmissions and failures that can occur with them
• K 2 automated transmission components such as wiring, solenoids, sensors, actuators, force motors and ECMs, and their operation
• K 3 data links and communication with engine ECM
• K 4 automated transmission diagnostic equipment and procedures as outlined by the manufacturer
• K 5 basic principles of electricity and circuit components
• K 6 basic principles of schematic interpretation

Sub-task - E-23.01 Services automated transmissions.

Key Competencies

• E-23.01.01 perform sensory inspections of components to identify leaks, breaks and excessive wear
• E-23.01.02 check and perform software updates following manufacturers’ recommended procedures
• E-23.01.03 replace oil according manufacturers’ specifications and maintenance schedule
• E-23.01.04 recycle and/or dispose of consumable components according to jurisdictional regulations

Sub-task - E-23.02 Diagnoses automated transmissions.

Key Competencies

• E-23.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-23.02.02 perform sensory inspections such as checking for leaks and completing a road test to confirm complaint and establish a preliminary diagnosis
• E-23.02.03 perform diagnostic procedure by following troubleshooting tree or schematic supplied by manufacturer to determine failure
• E-23.02.04 ensure specialized tests are performed using diagnostic tools including computers or other specialized equipment provided by the manufacturer
• E-23.02.05 compare test results to manufacturers’ specifications or expected values to verify diagnosis
• E-23.02.06 interpret and record test results according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - E-23.03 Repairs automated transmissions.

Key Competencies

• E-23.03.01 remove and replace worn, damaged or faulty components such as valves, sensors, hoses, lines, actuators, ECMs, gaskets and wiring harnesses
• E-23.03.02 confirm most current version of software is installed in the ECM
• E-23.03.03 rebuild transmission to manufacturers’ specifications
• E-23.03.04 repair components such as wiring harnesses and connectors
• E-23.03.05 ensure road test is completed to verify repair operates to manufacturers’ specifications
• E-23.03.06 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 24 Services, diagnoses and repairs driveline systems.

Context

The driveline provides a mechanical linkage between the transmission and the differential. A truck and transport mechanic must understand the influence of driveline length, angles and correct phasing on the driveline system.

Required Knowledge

• K 1 methods of installing and phasing of driveline systems
• K 2 yoke and u-joint installation and removal
• K 3 conditions requiring repair such as vibration, noise and other reported problems
• K 4 wear limits, driveline angles and support bearings according to manufacturers’ specifications
• K 5 serviceable and non-serviceable driveline systems
• K 6 correct orientation of drive shaft
• K 7 function of driveline savers
• K 8 PTOs

Sub-task - E-24.01 Services driveline systems.

Key Competencies

• E-24.01.01 perform sensory inspections of yokes, u-joints, mounting hardware and steady bearings to identify worn, damaged, loose or defective components
• E-24.01.02 lubricate serviceable u-joints and slip-joints

Sub-task - E-24.02 Diagnoses driveline systems.

Key Competencies

• E-24.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-24.02.02 inspect u-joints, slip-joints and steady bearings to establish a preliminary diagnosis
• E-24.02.03 check driveshaft for correct phasing and orientation
• E-24.02.04 perform specialized testing procedures to determine cause of complaint or failure using diagnostic equipment such as vibration analyzer, angle gauges and computers
• E-24.02.05 confirm proper driveline alignment by checking ride height and driveline angles
• E-24.02.06 compare test results to manufacturers’ specifications or expected values to verify diagnosis

Sub-task - E-24.03 Repairs driveline systems.

Key Competencies

• E-24.03.01 remove and replace worn, damaged or faulty components such as u-joints, steady bearings and slip joints
• E-24.03.02 perform adjustment procedures such as phasing, balancing and driveline angle adjustment to ensure proper operation
• E-24.03.03 lubricate u-joints and slip joints according to manufacturers’ specifications
• E-24.03.04 verify repair by ensuring a road test is performed

Task 25 Services, diagnoses and repairs differentials.

Context

The differential assembly transfers power from the engine and transmission to the wheels. Truck and transport mechanics must be able to service, diagnose and repair complaints related to differential assembly.

Required Knowledge

• K 1 types of differentials such as locking, two-speed, limited slip and outboard planetary drive
• K 2 weight ratings and gear ratios
• K 3 methods of securing hubs to spindles such as pre-set and conventional bearing types
• K 4 differential components such as seals, axles, gaskets, hubs, gears and bearings
• K 5 differential lock activating methods such as air and electric
• K 6 conditions that indicate differential needs servicing such as noise and interaxle differential lock not working
• K 7 common faults such as missing teeth in crown and pinion gears, broken shift fork in power dividers, lack of lubrication and broken axles
• K 8 types of lubrication

Sub-task - E-25.01 Services differentials.

Key Competencies

• E-25.01.01 clean components such as breathers and vents
• E-25.01.02 check oil level and visually inspect oil condition during scheduled maintenance
• E-25.01.03 replace oil and filters according to manufacturers’ specifications
• E-25.01.04 inspect seals and gaskets for leaks
• E-25.01.05 service bearings and planetary gear sets according to manufacturers’ specifications
• E-25.01.06 recycle and/or dispose of oil and filter according to jurisdictional regulations

Sub-task - E-25.02 Diagnoses differentials.

Key Competencies

• E-25.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-25.02.02 check oil level and condition
• E-25.02.03 inspect components such as fork, bearings, crown and pinion gears for incorrect backlash, wear or incorrect pre-load
• E-25.02.04 ensure road test is performed to confirm complaint
• E-25.02.05 perform diagnostic procedure by following troubleshooting tree or schematic supplied by manufacturer to determine failure

Sub-task - E-25.03 Repairs differentials.

Key Competencies

• E-25.03.01 remove and replace worn, damaged or faulty components such as seals, gaskets, bearings and outboard planetary gear sets
• E-25.03.02 clean components such as vents, housings, gasket surfaces, gears and hubs to remove debris and contaminants
• E-25.03.03 repair components such as housings and spindle threads
• E-25.03.04 perform overhaul procedures such as setting and adjusting preload and backlash, and checking and adjusting crown and pinion gear tooth pattern
• E-25.03.05 verify repair using methods such as marking paste, dial indicators and weight scale
• E-25.03.06 adjust wheel bearings according to manufacturers’ specifications
• E-25.03.07 refill housing using lubricant according to manufacturers’ specifications
• E-25.03.08 ensure road test is performed to confirm repairs
• E-25.03.09 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 26 Services, diagnoses and repairs drive train retarders.

Context

Drive train retarders are an optional component used to assist and extend the life of the primary braking system. They can be separate or combined with another component of the drive train system.

Required Knowledge

• K 1 types of retarder systems such as driveline and transmission
• K 2 specialized diagnostic equipment such as multimeters, diagnostic software and pressure gauges
• K 3 automatic transmissions and retarder components
• K 4 components such as generators, solenoids, pressure switches, potentiometers, valves, actuators and wiring harnesses
• K 5 common faults such as pressure loss, corroded wiring, weak performance and intermittent operation
• K 6 troubleshooting trees and wiring schematics

Sub-task - E-26.01 Services drive train retarders.

Key Competencies

• E-26.01.01 check for fluid leaks, secure component mountings, and damaged or corroded wiring
• E-26.01.02 update software
• E-26.01.03 replace oil and filter according to manufacturers’ specifications and maintenance schedule
• E-26.01.04 recycle and/or dispose of consumable components according to jurisdictional regulations

Sub-task - E-26.02 Diagnoses drive train retarders.

Key Competencies

• E-26.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• E-26.02.02 check for external leaks and loose, broken, damaged or corroded wiring
• E-26.02.03 perform diagnostic procedure by following troubleshooting tree or schematic supplied by manufacturer to determine failure
• E-26.02.04 ensure road test is performed to assess components for wear, damage or defects using diagnostic tools such as pressure gauges, computers, multimeters or other specialized equipment provided by the manufacturer
• E-26.02.05 interpret fault codes and test results to ensure operation is within manufacturers’ specifications
• E-26.02.06 record test results and inspection findings according to manufacturers’ requirements for warranty

Sub-task - E-26.03 Repairs drive train retarders.

Key Competencies

• E-26.03.01 remove and replace worn, damaged or faulty components such as solenoids, valves, sensors, pressure switches, potentiometers, lines, wiring and connectors
• E-26.03.02 confirm most current version of software is installed in the ECM
• E-26.03.03 rebuild transmission to manufacturers’ specifications
• E-26.03.04 repair driveline retarder components to manufacturers’ specifications
• E-26.03.05 remove and replace internal transmission components such as torque converters, pumps, clutch pack assemblies and valve bodies according to manufacturers’ specifications
• E-26.03.06 ensure road test is performed to verify repairs meet manufacturers’ specifications
• E-26.03.07 document that repairs and verifications have been performed for warranty, liability, future reference and tracking