wheels and hubs 2

Towing and Steering Issues

  • Excessive Towing: Definition and characteristics were discussed.
  • Feathering:
    • Described as a wear pattern on tires that appears smooth from the inside and rough on the outside.
    • Indicative of alignment issues.

Wheel Alignment and Steering Characteristics

  • Camber:
    • Positive Camber: Outside edges of the wheel are higher.
    • Negative Camber: Inside edges of the wheel are higher.
  • Discussion focused on alignment adjustments and tolerances for Class Eight trucks.
  • Wandering Steering:
    • Defined as the steering wheel moving erratically when the driver attempts to hold it straight.
    • Causes include play in tie rod ends and linkage, and issues in the steering box.
    • Older vehicles may exhibit significant play, e.g., older Chevy trucks with excess wheel play.

Wheel Mounting and Types

  • Two main types of wheel and hub mounting:
    1. Locking Hub: Older style with locking mechanisms.
    2. Modern Wheels: Typically a one-piece wheel without slip rings.
  • Wedge and Clamp:
    • A shim or wedge is used to secure the wheel nut against the hub, ensuring tightness and preventing loosening.
  • Durability:
    • Older wheels are often more durable compared to aluminum wheels, which are prone to dents.
    • Used often on gravel trucks and older farm vehicles.
  • Balancing Tires:
    • Tires require proper lateral balance to prevent movement.
    • A recommended method involves tightening opposite wheel nuts after spinning the wheel to identify lateral runout.
    • Max lateral runout of one-eighth of an inch is acceptable for steer axles and a quarter inch for drive axles.
      • If exceeded, the issue can be felt by the driver through steering or vibrations.

Wheel Spacing and Mounting Techniques

  • Dayton Style Wheels: Specific mounting procedures discussed.
  • Wheel Spacing:
    • A collapsible spacer is used between wheels to accommodate bulging under load.
  • Hub Pilot vs. Stud Pilot Wheels:
    • Hub Pilot wheels center on the hub; Stud Pilot wheels center on the wheel nuts themselves.
    • It’s crucial to use the correct wheel type for each hub profile to ensure proper fitment.

Wheel Nut Torque Procedures

  • Retorque Procedure:
    • Post-installation, especially on duals, inside wheel nuts need to be retorqued after loosening outer wheel nuts.
  • Indicators:
    • Use of indicators that slide over flange nuts to alert if nuts are loose.
    • These indicators help drivers quickly identify (and address) loose wheel nuts.
  • Surface Cleanliness:
    • Emphasized the importance of clean mating surfaces to avoid build-up (e.g., paint) that can lead to loose nuts over time.

Wheel Bearings and Seals

  • Wheel Bearing Adjustments:
    • Endplay and axial play were discussed in relation to bearing adjustment.
    • Axial play target for Class Eight trucks: 1 to 5 thousandths of an inch; radial play should be zero.
  • Proper installation and sealing methods were addressed, emphasizing that seals must be positioned correctly to prevent leaks.
  • Signs of contamination and leakage, such as oil staining on tires, warrant immediate attention and maintenance.

General Maintenance Procedures

  • Importance of checking all components, particularly bearings and seals, after adjustments or installations.
  • Regular inspections should focus on bearing play, potential contamination, and integrity of connected parts.
  • Correct installation tools should be utilized to avoid damage during installations, as well as using rubber or brass materials to minimize risk of bearing damage during adjustments.