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:
Locking Hub: Older style with locking mechanisms.
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.