Block F – Steering, Chassis/Frames, Suspension, Wheels, Hubs And Tires

Trends

Spoked hubs are less common, being replaced with hub pilot systems. There is also a trend towards a tighter turning radius.

There is an increase in load capacities, resulting in the need for wider tires and additional axles to meet road standards. Super single tires are being introduced in the industry. They are lighter and have a larger foot print than the dual wheels.

Related Components (including, but not limited to)

Steering system components: steering boxes, steering wheel, steering knuckles, steering column, pitman arms, tie rods, king pins, connecting rods, drag links, power steering components.

Chassis/frame components: frame rails, cross members, mounts, hangers, gussets, monocoque chassis.

Suspension components: axles (drive, steering, auxiliary), springs, bushings, air springs, levelling valves, leaf springs, spring overloads, stoppers, spring hangers, shackles, saddles, shocks, torsion bars, walking beam, u-bolts.

Hitches and couplers: jaw, locks, handles, ball and stud, sliders, rails, saddles, pintles, safety chains, pads, forks.

Tires, wheels and hubs: belts, tread, tubes, sidewall, seals, rims, spacers (corrosion control, wheel spacers), wedges, valve stems, studs, nuts, super singles, tandem, cup and cone bearings.

Tools and Equipment

See Appendix A.

Task 27 Services, diagnoses and repairs steering system.

Context

Truck and transport mechanics diagnose and service steering systems and components in order to ensure the safe and correct operation of the vehicle.

Steering systems are designed to allow the driver to control the direction of the vehicle by turning the front wheels.

Required Knowledge

• K 1 operating principles of steering systems
• K 2 types of steering systems such as integral, linkage, and rack and pinion
• K 3 steering system components such as steering boxes, pitman arms, tie rods, king pins, drag links and power steering components
• K 4 master and slave steering systems
• K 5 common faults such as tire wear, bent tie rods and worn drag link
• K 6 steering geometry and alignment such as caster, camber, toe-in and toe-out
• K 7 chassis/frame components such as frame rails, cross members, mounts, hangers and gussets
• K 8 monocoque chassis design
• K 9 chassis/frame fastening systems
• K 10 common chassis/frame faults such as bending, cracking, corrosion and missing fasteners
• K 11 types of suspensions such as air ride, spring, solid block and combination
• K 12 suspension components such as spring hangers, shackles, saddles, shocks, torsion bars, walking beam and u-bolts
• K 13 axle applications such as steering, drive and auxiliary
• K 14 common suspension faults such as broken springs, air springs, u-bolts, leaking shocks and worn bushings
• K 15 types of hitches and couplers such as pintle hitch, fifth-wheel hitch and ball hitch
• K 16 hitch and coupler applications
• K 17 common faults such as out-of-adjustment and twisted, bent and worn components
• K 18 types of tires such as radial and bias
• K 19 tire load ranges, pressures, profiles and sizes
• K 20 steering and drive tires
• K 21 types of wheels such as aluminum and steel
• K 22 types of hubs such as spoked, hub pilot and stud pilot
• K 23 tire components such as belts, tread, tubes and sidewall
• K 24 wheel components such as rims, spacers, wedges and valve stems
• K 25 hub components such as studs, nuts and spacers
• K 26 common faults such as cracked rims, holes in tires, broken studs and worn locks

Sub-task - F-27.01 Services steering system.

Key Competencies

• F-27.01.01 perform sensory inspections of steering system to identify worn, damaged or defective components such king pins, drag links, steering boxes, pitman arms and hydraulic cylinders
• F-27.01.02 measure steering system components such as king pins, drag links and tie rods for end play to determine if they meet manufacturers’ specifications and jurisdictional requirements
• F-27.01.03 remove and replace consumable components such as oils and filters according manufacturers’ specifications and employer maintenance schedule to minimize breakdowns
• F-27.01.04 recycle and/or dispose of consumable components according to jurisdictional regulations
• F-27.01.05 record service information and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking
• F-27.01.06 lubricate components such as tie rods, king pins and u-joints according to manufacturers’ recommendations

Sub-task - F-27.02 Diagnoses steering system.

Key Competencies

• F-27.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• F-27.02.02 perform sensory inspections such as looking for leaks, feeling for vibrations during road testing and visually inspecting tire for incorrect wear pattern to confirm complaint and establish a preliminary diagnosis
• F-27.02.03 perform diagnostic procedure by following troubleshooting tree or schematic supplied by manufacturer to determine failure
• F-27.02.04 perform specialized testing procedures such as performance, pressure and volume tests to assess components for wear, damage or defects using tools and equipment such as pressure gauges, dial indicators and prybars
• F-27.02.05 compare test results to manufacturers’ specifications or expected pressure values to verify diagnosis
• F-27.02.06 perform failure analysis to determine root cause of failure
• F-27.02.07 record test results and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking
• F-27.02.08 interpret tire wear patterns

Sub-task - F-27.03 Repairs steering systems.

Key Competencies

• F-27.03.01 remove and replace worn, damaged or faulty components such as king pins, drag links, steering boxes, pitman arms and hydraulic cylinders
• F-27.03.02 rebuild components such as power steering box and hydraulic cylinders by replacing seals, o-rings and internal components of steering box, according to manufacturers’ specifications
• F-27.03.03 repair or replace components such as steering boxes, pumps, hoses, lines, seals, u-joints and reservoirs according to manufacturers’ specifications
• F-27.03.04 perform adjustment procedures such as poppet valves, pitman arms and worm gear to ensure proper operation of component/equipment
• F-27.03.05 verify repair by using methods such as road testing, front end alignments, load testing and sensory observations
• F-27.03.06 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 28 Services, diagnoses and repairs chassis/frames.

Context

The purpose of the chassis/frame is to fasten all the vehicle components. Truck and transport mechanics service, diagnose and repair chassis/frame to ensure vehicle integrity.

Required Knowledge

• K 1 frame straightening procedures
• K 2 types of suspension such as air ride, spring, solid block and combination
• K 3 OEM specifications such as wear limits and load capacity
• K 4 jurisdictional requirements
• K 5 chassis/frame components such as frame rails, cross members, mounts, hangers and gussets
• K 6 chassis/frame fastening systems
• K 7 monocoque chassis design

Sub-task - F-28.01 Services chassis/frames.

Key Competencies

• F-28.01.01 clean frame rails, cross-members and gussets
• F-28.01.02 perform sensory inspections of frame rails, cross-members and gussets for loose mounting hardware, cracks and distortions such as corrosion
• F-28.01.03 measure frame rails to determine if the frame meets manufacturers’ specifications

Sub-task - F-28.02 Diagnoses chassis/frames.

Key Competencies

• F-28.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• F-28.02.02 perform sensory inspections such as looking for cracked or damaged frames, corrosion, and missing or loose hardware to establish a preliminary diagnosis
• F-28.02.03 perform failure analysis using diagnostic equipment such as laser alignment tools, calipers and straight edges to determine root cause of failure
• F-28.02.04 record test results and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-28.03 Repairs chassis/frames.

Key Competencies

• F-28.03.01 remove and replace worn, damaged or faulty components such as cross-members, gussets and mounting hardware
• F-28.03.02 repair and replace components such as cross-members, gussets and frame rail by welding and plating according to manufacturers’ specifications
• F-28.03.03 verify repair using tools such as laser alignments, calipers and straight edges
• F-28.03.04 modify chassis/frame such as adding inserts, drilling frames and adjusting length
• F-28.03.05 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 29 Services, diagnoses and repairs suspension.

Context

Truck and transport mechanics service, diagnose and repair suspensions to ensure smooth driving conditions. Suspensions distribute load throughout the frame and withstand road hazards by absorbing energy.

Required Knowledge

• K 1 types of suspension such as air ride, spring, solid block and combination
• K 2 suspension components such as spring hangers, shackles, saddles, shock absorbers, torsion bars, walking beams and u-bolts
• K 3 manufacturers’ specifications such as wear limits and load capacity
• K 4 related effect of component failure such as defective springs, ride height valves, blown air bags, chaffed air lines, defective rubber blocks and worn bushings

Sub-task - F-29.01 Services suspension.

Key Competencies

• F-29.01.01 clean suspension components
• F-29.01.02 perform sensory inspections of suspension to identify worn, damaged or defective components such bolster springs, I- beams, torque rods, ride height valves and air bags
• F-29.01.03 measure suspension components such as frame for ride height and bushings for excessive play to determine if they meet manufacturers’ specifications
• F-29.01.04 release stored energy by draining the air tank and spring tension
• F-29.01.05 adjust ride height valve according to manufacturers’ specifications
• F-29.01.06 lubricate suspension components
• F-29.01.07 record service information and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-29.02 Diagnoses suspension.

Key Competencies

• F-29.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• F-29.02.02 perform sensory inspections of suspension to identify worn, damaged or defective components such as bolster springs, I beams, torque rods, ride height valves and air bags to confirm complaint and establish a preliminary diagnosis
• F-29.02.03 perform testing procedures to assess components for wear, damage or defects using tools and equipment such as tape measures, soapy water and dial indicators
• F-29.02.04 compare test results to manufacturers’ specifications or expected values to verify diagnosis
• F-29.02.05 record test results and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-29.03 Repairs suspension.

Key Competencies

• F-29.03.01 remove and replace worn, damaged or faulty components such as springs, spring guides, bushings and torque rods
• F-29.03.02 repair components such as air lines, air springs and leaf spring assemblies according to manufacturers’ specifications
• F-29.03.03 perform adjustment procedures such as setting ride height valves to ensure proper operation of component/equipment
• F-29.03.04 verify repair by using methods such as road testing, load testing and sensory observations
• F-29.03.05 use welding and cutting equipment to repair axle stops, shackle assemblies and hanger assemblies
• F-29.03.06 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 30 Services, diagnoses and repairs hitches and couplers.

Context

Truck and transport mechanics service, diagnose and repair hitches and couplers to ensure that trailers stay coupled to the lead vehicle in a safe manner.

Required Knowledge

• K 1 types of hitches and couplers such as pintle hitch, fifth-wheel hitch and ball hitch
• K 2 hitch and coupler applications
• K 3 common faults such as out-of-adjustment and twisted, bent and worn components
• K 4 wear limits and load capacities of hitches and coupler components

Sub-task - F-30.01 Services hitches and couplers.

Key Competencies

• F-30.01.01 clean 5^th wheel, slide rails and pintle components
• F-30.01.02 perform sensory inspections of 5^th wheel and pintles to identify worn, damaged or defective components such bushings, jaws, slide rail locks and clevis pin
• F-30.01.03 measure hitch and coupler components such as 5^th wheel plate, side rail locks, bushings, pins and jaws for play to determine if they meet manufacturers’ specifications
• F-30.01.04 adjust 5^th wheel jaws and side rail locks to meet manufacturers’ specifications
• F-30.01.05 lubricate components
• F-30.01.06 record service information and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-30.02 Diagnoses hitches and couplers.

Key Competencies

• F-30.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• F-30.02.02 perform sensory inspections of 5^th wheel and pintles to identify worn, damaged or defective components such bushings, jaws, slide rail locks and clevis pin to confirm complaint and establish a preliminary diagnosis
• F-30.02.03 perform specialized testing procedures such as testing for play to assess components for wear, damage or defects using tools and equipment such as king pin tool
• F-30.02.04 test hitch and coupler operation
• F-30.02.05 compare test results to manufacturers’ specifications or expected values to verify diagnosis
• F-30.02.06 record test results and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-30.03 Repairs hitches and couplers.

Key Competencies

• F-30.03.01 remove and replace worn, damaged or faulty components such as jaws, 5^th wheels, springs and pins
• F-30.03.02 repair and rebuild 5^th wheel components such as jaws, pins, springs and bushings by using rebuild kits, according to manufacturers’ specifications
• F-30.03.03 adjust 5^th wheel to ensure proper operation of component/equipment
• F-30.03.04 verify repair by using methods such as coupling and uncoupling
• F-30.03.05 lubricate components
• F-30.03.06 document that repairs and verifications have been performed for warranty, liability, future reference and tracking

Task 31 Services, diagnoses and repairs tires, wheels and hubs.

Context

Truck and transport mechanics service, diagnose and repair tires, wheels and hubs to ensure that the truck will be rolling properly on the road.

Required Knowledge

• K 1 tire load ranges, pressures, profiles and sizes
• K 2 steering and drive tires
• K 3 types of wheels such as aluminum and steel
• K 4 types of hubs such as spoked, hub pilot, and stud pilot
• K 5 tire components such as belts, tread, tubes and sidewall
• K 6 wheel components such as rims, spacers, wedges and valve stems
• K 7 hub components such as studs, nuts and spacers
• K 8 common faults such as cracked rims, holes in tires, broken studs, worn locks, and worn spacers
• K 9 torque values
• K 10 wheel balancing
• K 11 hazards associated with tire inflation
• K 12 hazards associated with removal of tires such as spoke wheels and wedges

Sub-task - F-31.01 Services tires, wheels and hubs.

Key Competencies

• F-31.01.01 perform sensory inspections of tires, wheels and hubs to identify worn, damaged or defective components such oil leaks from the hubs, air leaks from tires and cracked rims
• F-31.01.02 measure tire components such as tread depth for wear and air pressure for air leaks, to determine if they meet manufacturers’ specifications
• F-31.01.03 measure hub components such as bearing end play to determine if they meet manufacturers’ specifications and jurisdictional requirements
• F-31.01.04 torque nuts to ensure fasteners meet manufacturers’ specifications
• F-31.01.05 release stored energy by draining air from tires
• F-31.01.06 remove and replace consumable components such as oils in hubs according manufacturers’ specifications
• F-31.01.07 recycle and/or dispose of consumable components according to jurisdictional regulations
• F-31.01.08 adjust tire pressure according to manufacturers’ specifications
• F-31.01.09 torque tire according to manufacturers’ specifications
• F-31.01.10 recognize hazards associated with removal of tires such as spoke wheels and wedges
• F-31.01.11 identify mismatched tires by casing and tread depth
• F-31.01.12 record service information and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-31.02 Diagnoses tires, wheels and hubs.

Key Competencies

• F-31.02.01 obtain details of symptoms associated with complaint to establish a starting point for diagnostics
• F-31.02.02 perform sensory inspections of tires, wheels and hubs to identify worn, damaged or defective components such oil leaks from hubs, air leaks from tires and cracked rims to confirm complaint and establish a preliminary diagnosis
• F-31.02.03 perform diagnostic procedure by following troubleshooting tree supplied by manufacturer to determine failure
• F-31.02.04 measure components for wear, damage or defects using diagnostic equipment such as dial indicators, torque wrenches, air gauges, tire pressure/heat warning devices and tread depth gauges
• F-31.02.05 compare test results to manufacturers’ specifications or expected values to verify diagnosis
• F-31.02.06 perform failure analysis to determine root cause of failure
• F-31.02.07 record test results and inspection findings according to manufacturers’ requirements for warranty, and for future reference and tracking

Sub-task - F-31.03 Repairs tires, wheels and hubs.

Key Competencies

• F-31.03.01 remove and replace worn, damaged or faulty components such as tires, rims, bearings and studs
• F-31.03.02 rebuild components such as hub assemblies by replacing bearings and races according to manufacturers’ specifications
• F-31.03.03 repair components such as tires and hub assemblies by replacing seals, bearings, races, patches and plugs, according to manufacturers’ specifications
• F-31.03.04 perform procedures such as bearing adjustment to ensure proper operation of component/equipment
• F-31.03.05 adjust air pressure and run-out and torque on spoke wheels according to manufacturers’ specifications
• F-31.03.06 verify repair by using methods such as wheel alignment, road testing and checking for end play, according to manufacturers’ specifications
• F-31.03.07 document that repairs and verifications have been performed for warranty, liability, future reference and tracking