Peterbilt 337 Light Duty Truck Inspection Checklist

Comprehensive inspection procedures for Peterbilt 337 medium-duty trucks in various vocational applications.

Peterbilt 337 Inspection Overview

The Peterbilt 337 is a versatile Class 7 medium-duty truck designed for various vocational applications including beverage delivery, construction, utility service, and more. With a GVWR range of 26,000 to 33,000 pounds, the 337 features a setback front axle, aluminum cab, and numerous upfit options to meet specific industry needs. This inspection checklist provides fleet managers, technicians, and operators with detailed procedures for maintaining these versatile trucks, ensuring safety, compliance, and optimal performance across diverse applications. Regular inspections are critical for reducing downtime, extending service life, and maintaining the value of these specialized vocational vehicles.

PACCAR Engine and Powertrain Inspection

Verify these critical engine and powertrain components for the Peterbilt 337.

PACCAR PX-7/PX-9 Engine

  • Check engine oil level and condition
  • Inspect for fluid leaks around engine
  • Verify coolant level and condition
  • Check drive belts for proper tension and wear
  • Inspect air intake system and filter restriction
  • Check exhaust system for leaks or damage
  • Verify turbocharger operation and integrity
  • Inspect engine mounts for security and wear

Aftertreatment System

  • Check DEF fluid level and quality
  • Inspect DPF restriction indicator
  • Verify SCR system operation
  • Check for exhaust leaks before/after DPF
  • Inspect DEF lines for crystallization
  • Verify aftertreatment warning indicators
  • Check exhaust system mounting points
  • Inspect exhaust pipe integrity and clearance

Transmission Inspection

  • Check transmission fluid level and condition
  • Inspect for transmission leaks
  • Verify shift linkage adjustment (manual)
  • Test shifting through all gears
  • Check PTO operation (if equipped)
  • Inspect transmission mounts
  • Check for unusual noise during operation
  • Verify clutch free play (manual transmission)

Cooling System

  • Check coolant level and freeze protection
  • Inspect radiator for damage or blockage
  • Verify fan operation and clutch engagement
  • Check coolant hoses and clamps
  • Inspect water pump for leaks or noise
  • Test thermostat operation
  • Check radiator cap pressure relief
  • Verify radiator mounting and isolation

Brake System and Running Gear

Verify these critical brake and chassis components specific to the Peterbilt 337.

Air Brake System

  • Perform complete air brake check procedure
  • Check air governor cut-in/cut-out pressure
  • Verify low air pressure warning device
  • Inspect air tanks and drain valves
  • Test air dryer operation
  • Check for air system leaks
  • Verify air compressor operation
  • Test parking brake application and release

Brake Components

  • Inspect brake drums/rotors for wear or damage
  • Check brake linings/pads for thickness
  • Verify slack adjuster stroke and operation
  • Inspect brake chambers for damage or leaks
  • Check brake hoses and lines for wear
  • Test ABS system function and warning lights
  • Verify brake balance front to rear
  • Check for brake dust pattern indicating problems

Steering System

  • Check steering wheel free play
  • Inspect steering gear box mounting
  • Verify power steering fluid level and condition
  • Check power steering hoses for leaks
  • Inspect steering linkage components
  • Verify king pins and bushings for wear
  • Check tie rod ends and drag link
  • Test steering for binding or unusual noise

Suspension System

  • Inspect front leaf springs and hangers
  • Check rear suspension components
  • Verify shock absorber operation and leaks
  • Inspect air suspension components (if equipped)
  • Check suspension U-bolts and fasteners
  • Verify axle alignment
  • Inspect frame attachments near suspension
  • Check for signs of suspension overloading

Wheels and Tires

  • Check tire pressure in all positions
  • Inspect tire tread depth and wear patterns
  • Verify wheel condition (no cracks or damage)
  • Check lug nuts for proper torque
  • Inspect valve stems and caps
  • Verify proper tire size and rating
  • Check wheel bearing condition and adjustment
  • Inspect for dual spacing and matching

Driveline Components

  • Inspect driveshaft for damage or wear
  • Check U-joints for looseness or wear
  • Verify center bearing condition (if equipped)
  • Inspect driveline safety loops
  • Check differential oil level
  • Inspect differential housing for leaks
  • Verify axle breather operation
  • Check wheel seals for leakage

Chassis and Frame

  • Inspect frame rails for cracks or damage
  • Check cross members and gussets
  • Verify body mount attachments
  • Inspect frame for signs of overloading
  • Check trailer hitch mounting (if equipped)
  • Verify pintle hook condition (if equipped)
  • Inspect air and electrical connections
  • Check frame for improper welding or drilling

Fuel System

  • Check fuel tank mounting and security
  • Inspect for fuel leaks or seepage
  • Verify fuel cap condition and venting
  • Check fuel lines and connections
  • Inspect fuel filters for contamination
  • Verify water separator function
  • Check fuel tank for damage or corrosion
  • Inspect fuel system for modifications

Cab and Electrical Systems

Verify these cab and electrical components specific to the Peterbilt 337.

Cab Structure and Access

  • Inspect cab mounting points and bushings
  • Check cab tilt system function and locks
  • Verify doors open, close, and latch properly
  • Inspect door seals and weatherstripping
  • Check steps and grab handles for security
  • Verify windshield condition and visibility
  • Check mirrors for security and adjustment
  • Inspect seatbelts for function and wear

Interior Components

  • Check all gauges for proper operation
  • Verify warning lights illuminate during startup
  • Test HVAC system operation
  • Check wipers and washers function
  • Inspect seats for damage and adjustment
  • Verify steering wheel adjustment
  • Check all controls and switches operation
  • Inspect floor coverings and trim condition

Electrical System

  • Check battery condition and connections
  • Verify alternator output (13.5-14.5V)
  • Test starter operation
  • Inspect all wiring for damage or chafing
  • Check fuse panel and circuit breakers
  • Verify ground straps and connections
  • Test interior and exterior lighting
  • Check electronic control modules for codes

Lighting and Visibility

  • Test headlights (high and low beam)
  • Check turn signals and hazard lights
  • Verify brake lights and tail lights
  • Inspect clearance and marker lights
  • Check backup lights and alarm
  • Verify license plate light
  • Inspect all reflectors and conspicuity tape
  • Test work lights (if equipped)

Vocational Equipment Inspection

Verify these specialized vocational components often found on Peterbilt 337 trucks.

Hydraulic System

  • Check hydraulic fluid level and condition
  • Inspect hydraulic pump operation
  • Verify hydraulic lines for leaks or damage
  • Test hydraulic controls for proper function
  • Check hydraulic cylinder operation
  • Inspect hydraulic tank mounting
  • Verify pressure relief valve settings
  • Check PTO engagement for hydraulic system

Aerial Lift/Bucket (If Equipped)

  • Inspect boom and lift components
  • Check outrigger function and interlocks
  • Verify emergency lowering system
  • Test all boom controls and limits
  • Inspect bucket and liner condition
  • Check insulation integrity (if insulated)
  • Verify all safety equipment and decals
  • Test operator restraint systems

Dump Body (If Equipped)

  • Inspect dump body structure and mounting
  • Check hoist cylinders and pins
  • Verify tailgate operation and latching
  • Test dump control valve function
  • Inspect body prop rod operation
  • Check body-to-frame clearance
  • Verify cab shield integrity
  • Inspect body tarp system (if equipped)

Flatbed/Stake Body (If Equipped)

  • Inspect bed floor and structure
  • Check stake pockets and side racks
  • Verify tie-down points integrity
  • Inspect headboard condition
  • Check underbed storage compartments
  • Verify ramps and lift gate (if equipped)
  • Inspect body mounting to frame
  • Check lighting on body and clearance

Crane/Material Handling (If Equipped)

  • Inspect crane mounting and stability
  • Check all boom sections and extensions
  • Verify outrigger operation and pads
  • Test all crane controls and functions
  • Inspect hook, block, and cable condition
  • Check hydraulic system for leaks
  • Verify load chart and safety decals
  • Test overload protection systems

Utility Service Body (If Equipped)

  • Inspect compartment doors and latches
  • Check drawer slides and mechanisms
  • Verify master locking system function
  • Inspect internal shelving and dividers
  • Check compartment lighting
  • Verify weathersealing integrity
  • Inspect body mounting to frame
  • Check ladder rack and accessories

Towing and Recovery (If Equipped)

  • Inspect wrecker boom components
  • Check winch operation and cable condition
  • Verify wheel lift and attachments
  • Test underlift operation and controls
  • Inspect tow chains and hooks
  • Check bed/carrier hydraulic function
  • Verify PTO engagement for recovery systems
  • Inspect all safety lighting and accessories

Auxiliary Power Systems

  • Check auxiliary generators (if equipped)
  • Inspect air compressor systems
  • Verify auxiliary hydraulic systems
  • Test welding systems (if equipped)
  • Check auxiliary fuel systems
  • Verify power inverters and electrical outlets
  • Inspect auxiliary cooling systems
  • Check auxiliary engine controls and interfaces

Safety and Compliance Inspection

Verify these safety and compliance components for the Peterbilt 337.

Required Safety Equipment

  • Verify fire extinguisher presence and charge
  • Check emergency reflective triangles
  • Inspect first aid kit (if required)
  • Check spare fuses availability
  • Verify safety chains and hooks
  • Inspect wheel chocks
  • Check high-visibility safety vest
  • Verify spill containment kit (if required)

Documentation Verification

  • Check vehicle registration and insurance
  • Verify annual inspection documentation
  • Inspect IFTA credentials (if applicable)
  • Check driver's license and endorsements
  • Verify medical card (if required)
  • Check DVIR completion and previous defects
  • Verify operating authority (if applicable)
  • Check permit documentation for specific operations

Specialized Safety Systems

  • Test backup alarm function
  • Verify backup camera operation (if equipped)
  • Check blind spot monitoring system (if equipped)
  • Inspect stability control system function
  • Verify collision avoidance system (if equipped)
  • Test lane departure warning (if equipped)
  • Check adaptive cruise control (if equipped)
  • Verify telematics system operation

Emissions Compliance

  • Verify DPF system status and regeneration
  • Check DEF level and system function
  • Inspect EGR system operation
  • Verify no check engine or emissions lights
  • Check for unauthorized emissions modifications
  • Verify emissions label is present
  • Test exhaust for visible smoke
  • Check that emissions control warranty is valid

Preventive Maintenance Schedule

Recommended maintenance intervals for Peterbilt 337 medium-duty trucks.

A-Service (10,000 miles)

  • Change engine oil and filter
  • Check all fluid levels
  • Lubricate chassis and suspension
  • Inspect belts and hoses
  • Check tire condition and pressure
  • Inspect brake system components
  • Check lights and electrical systems
  • Perform visual inspection of all systems

B-Service (20,000 miles)

  • Perform all A-Service items
  • Replace fuel filters
  • Service air cleaner
  • Inspect cooling system thoroughly
  • Check brake adjustment and lining wear
  • Inspect steering and suspension components
  • Check transmission and differential fluid
  • Inspect exhaust system and aftertreatment

C-Service (40,000 miles)

  • Perform all B-Service items
  • Change transmission fluid
  • Replace differential oil
  • Inspect wheel bearings and repack
  • Service cooling system
  • Inspect driveline components
  • Check all engine mounting bolts
  • Inspect cab and body mounting

D-Service (80,000 miles)

  • Perform all C-Service items
  • Replace coolant
  • Inspect valve adjustment
  • Service air system components
  • Check engine and aftertreatment components
  • Inspect hydraulic systems thoroughly
  • Service vocational equipment
  • Check all frame components and attachments

Common Vocational Applications

Specialized inspection considerations based on the Peterbilt 337's application.

Utility Service

  • Inspect boom integrity and dielectric testing
  • Check outrigger operation and stability
  • Verify line worker safety equipment
  • Inspect auxiliary power systems
  • Check material handling capabilities
  • Verify grounding systems and bonding
  • Inspect insulated tools and equipment
  • Check compartment organization and security

Construction/Excavation

  • Verify dump body structural integrity
  • Check load-bearing capacity
  • Inspect hydraulic system under load
  • Verify body prop safety mechanism
  • Check for material buildup and cleaning
  • Inspect suspension for overload damage
  • Verify trailer towing capabilities
  • Check chassis durability in off-road use

Delivery/Distribution

  • Inspect cargo securing mechanisms
  • Check lift gate operation and capacity
  • Verify cargo area interior condition
  • Inspect loading ramps and equipment
  • Check refrigeration units (if equipped)
  • Verify cargo tracking systems
  • Inspect route optimization technology
  • Check load distribution compliance

Emergency/Fire/Rescue

  • Verify emergency lighting and siren function
  • Check specialized equipment mounting
  • Inspect emergency power systems
  • Verify communication equipment operation
  • Check specialized tool storage and access
  • Inspect breathing apparatus systems
  • Verify safety equipment integrity
  • Check rapid deployment capabilities
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