10/4/2015 Lake Area Tech Diesel Technology DT220 Truck Preventive Maintenance

Heavy Duty Truck Systems Chapter 1 Introduction to Servicing Heavy-Duty Trucks

Without Trucks, America Stops

Trucking is vital to America General Information: The trucking industry is comprised of more than 500,000 for-hire, private and government fleets, including owner operators. It employs 9.7 million people, including 3.12 million drivers, and accounts for nearly 5% of the U.S. gross domestic product. Truly, trucking is an essential part of our economy and society.essential

Check out the American Trucking Association ATA

Weight Classifications Class 1 up to 6000 LBS GVW Class ,000 Class 310,001-14,000 Class 414,001-16,000 Class 516,001-19,500 Class 619,501-26,000 Class 726,001-33,000 Class 833,001 and over

Major manufacturers Freightliner Navistar Kenworth Mack Sterling Peterbilt Volvo Western Star

Cab Configurations ConventionalCab-over-engine

Cab Configurations Short conventionalLow cab forward

Truck Classification TRUCK TOTAL WHEELS DRIVEN WHEELS TOTAL AXLES DRIVE AXLES 4X X X X X X X88844

Truck and Trailer dimensions

Electrical systems Batteries Alternator Starter Series/Parallel switch Lighting Accessories

Clutches Two plate clutch Push type Pull type Clutch brake

Transmissions Twin countershafts Triple countershafts Automatic (Allison) Auto-shift (2 or 3 pedal) Lubrication Oil coolers

Drive shafts End yoke U-joint 1610 size is 5.312” across the lugs 1710 size is 6.094” across the lugs 1760 size is 7” across the lugs 1810 size is 7.547” across the lugs

Axles Weight rating –Steering axle—8,9, 12, 14, 16K lbs –Single rear axle—14, 17, 19, 23K lbs –Tandem axles—34, 36, 38, 40K lbs Power divider Axle ratio –Find numbers on end of pinion shaft on rear-rear axle

Steering Manual –Worm and roller, recirculating ball, cam and lever types Hydraulic Power assist Air power assist Integral power steering (most common) –TRW (Ross) –Sheppard

Suspension systems Hendrickson equalizing beam

Four Spring Four spring

Four air springs (bags)

Torsion bar Eight bag (Kenworth)

Wheels and Tires Cast spoke (Dayton) Steel disc (Budd) Aluminum disc Stud piloted Hub piloted

Brakes Hydraulic drum Hydraulic disc Air S-cam Air wedge Air disc NHTSA FMVSS 121 ABS senders/modules (6S/6M)

Retarders Jacobs engine brake Mack Dynatard® Cat Brakesaver® Exhaust brake Electrical retarder

Chassis Frame Rails Crossmembers Flange Web

Fifth wheel Stationary Sliding Air slide elevating

HVAC Cab HVAC Sleeper HVAC APU

Electronic controls Engines Transmissions ABS Safety radar multiplexing

Fleet operations Linehaul JIT LTL P&D Courier DCC Vocational Renting and leasing O/O

Shops Fleets Dealerships Independent Specialty shops others

Jobs Service tech Specialty tech Service writer Parts manager Shop supervisor Service manager

As always, read the summary Remember, without trucks America stops