1. Introduction To Servicing Heavy-Duty Trucks
Chapter 1
Introduction To Servicing Heavy-Duty Trucks

2. Objectives (1 of 2) Explain basic truck classifications.
Define gross vehicle weight.
Classify a truck by the number of axles it has.
Identify an on-highway truck’s major systems and their related components.
Identify various career opportunities in the heavy-duty trucking industry.

3. Objectives (2 of 2)
Understand and explain the basic job classifications the heavy-duty truck industry offers to trained technicians with a sound understanding of truck systems.
Understand the ASE certification program and how it benefits technicians.

4. Truck Classifications (1 of 2)
Trucks are classified by their gross vehicle weight.
Light-duty
Classes 1-3
Medium duty
Classes 4-6
Heavy-duty
Classes 7 and 8
See Table 1-1 on page 2 of the textbook.

5. Truck Classifications (2 of 2)
Trucks are also classified by their number of axles.
The total number of axles is indicated first, followed by the number of driven axles.
See Table 1-3 on page 3 of the textbook.

6. Heavy-duty Trucks (1 of 4)
Engines
Heavy-duty trucks are powered exclusively by diesel engines.
More powerful
Less downtime for repairs
More dependable
Current highway diesel engines are electronically controlled.
Electrical systems
Multiple batteries
Heavy-duty charging systems
Heavy-duty starting systems

7. Heavy-duty Trucks (2 of 4)
Drive Shafts
Axles
Steering axles
Differentials
Lift axles
Steering
Suspension systems
Leaf spring
Rubber cushion
Air suspension
Wheels and tires
Clutches
Push vs. pull-type clutches
Two plate clutches
Transmissions
Conventional
Semi-automated
Fully automatic
Multiple countershaft designs

8. Heavy-duty Trucks (3 of 4)
Wheels and tires
Cast spoke
Steel disc
Aluminum disc
Wide base disc
Brakes
Highway trucks use air brakes exclusively.
Current tractors and trailers are required to be equipped with antilock brakes.
Vehicle retarders
Engine brakes
Exhaust brakes
Hydraulic retarders
Electric retarders
Chassis frame
Fifth wheels
Fifth wheel
Kingpin

9. Heavy-duty Trucks (4 of 4)
Heating/air conditioning
Electronic controls
Computerized control systems
Engines
Transmissions
Climate controls
Suspension
Brakes
Other systems
Multiplexing

10. Career Opportunities
The number of trucks in America is increasing while the number of qualified technicians is decreasing.
Fleet operations
Fleet shops
Dealership shops
Independent truck repair shops
Specialty service shops
Other truck shops

11. Job Classifications (1 of 2)
Service technicians
Certification
ASE
Specialty technicians
Service writer
Parts manager
Shop supervisor

12. Job Classifications (2 of 2)
Service manager
Advancement in the profession
Vocational/technical schools
Fleet training programs
Manufacturer training programs

13. Summary (1 of 4)
Although the number of trucks and automobiles in America is increasing, the number of technicians available to service and maintain them is decreasing.
Trucks are classified by their gross vehicle weight (GVW), the weight of the vehicle and maximum load, and by the number of axles they have.
Heavy-duty trucks have a GVW of 26,001 pounds or more.

14. Summary (2 of 4)
The major systems in on-highway trucks are engines, electrical systems, clutches, transmissions, drive shafts, axles, steering, suspension systems, wheels and tires, brakes, vehicle retarders, chassis frame, fifth wheel, heating and air-conditioning, electronic controls, and accessories.
Heavy-duty truck technicians are employed by fleet operations, fleet shops, dealership shops, independent truck service shops, specialty service shops, and other types of truck shops such as truck leasing and refuse haulers.

15. Summary (3 of 4) Job classifications in the heavy-duty truck industry
Service technician
Specialty technician
Service writer
Parts manager
Shop supervisor
Service manager
Oversees the entire service operation of a large dealership, fleet, or independent shop

16. Summary (4 of 4)
A successful heavy-duty truck technician must be able to maintain good customer relations and working relations; use effective communication skills; maintain a safe work environment; perform preventive maintenance; use tools and equipment properly; troubleshoot; correct problems by repairing or replacing; and upgrade skills and knowledge continuously.
Training for heavy-duty truck technicians is offered by vocational/technical schools, fleet training programs, and manufacturer training programs.
Heavy-duty truck technicians can obtain certification by the National Institute for Automotive Service Excellence (ASE) by passing written exams.