Trailer Frame And Axle Maintenance Issues

Improper alignment and maintenance will adversely affect the safety, performance and functional aspects of vehicles, having negative consequences for operating costs


The solution, according to Stertil-Koni, is to use four, heavy duty mobile column lifts - two at the wheels and two utilizing a kingpin cross beam that engages the trailer at the fifth wheel.

SAFETY FIRST

With trailer lifting, “safety, of course, is paramount,” Bowers emphasizes, “Before you begin, always lift on a firm foundation. Lift on level ground and be aware of wind loads.”

Next, bring in mobile lifting columns to the rear-most axle and maneuver the cross beam into place, locating it properly under the kingpin. At that point, engage the mobile lifting columns to the cross beams.

Stertil-Koni recommends using battery-powered, wireless mobile lifting columns, says Bowers. “In this way, an external power source is not required and it eliminates the possibility of the operator tripping due to messy wires or cables.

In today’s environment, many fleets are not taking the time, nor making the investment, to have trailer alignments done at shops that specialize in alignment and frame repair, observes Messina. Typically, this is done to avoid both the expense in moving trailers to these shops and the loss of revenue for the time they are out of service.

TRAILER AXLES

“An important thing to remember about trailer axle maintenance is that it is not the beam that requires most of the maintenance; it’s the components that are attached to it,” points out Keytoria S. King, product manager of trailer systems at Meritor, a leading global supplier of drivetrain, mobility, braking and aftermarket solutions for commercial vehicle and industrial markets. www.meritor.com. “Components should be regularly inspected for damage, wear, repair or replacement to prevent safety related incidents from occurring on the road.”

Instituting a regular inspection and maintenance schedule helps to reduce downtime and repair costs, while insuring vehicles meet state and federal regulations, Kings says. “Trailer axles should be inspected every six to 12 months. By doing so, the potential for costly breakdowns will be greatly reduced.”

Meritor provides the following recommendations:

Regular Component Inspections

1. Fasteners and tapped holes

Replace damaged fasteners and repair damaged tapped hole threads with the correct sized die.

2. Hubs and bearings

  • Ensure that they are cleaned, inspected and re-lubed.
  • Inspect for wheel bearing end play and seal leakage.
  • Replace bearing(s) if there are signs of wear, discoloration, roller cage damage, grooves, etches, cracks, etc.
  • Inspections and maintenance should be performed according to specifications in TMC RP 622A, Wheel Seal and Bearing Removal, Installation and Maintenance.

3. Brake spider

  • If cracks are found, replace the axle immediately.
  • If the weld on camshaft retainer is either damaged or worn, it can be replaced.

4. Automatic Slack Adjusters (ASA) and air chambers

  • It is common practice that ASA should not require manual adjustments in service. Refer to the manufacturer’s specifications to confirm.
  • The air chamber and ASA must be installed at the correct angle to ensure proper brake performance. Refer to the manufacturer’s specifications to inspect the angle.

5. Camshaft and camshaft bushings

  • Monitor for camshaft bushing wear and replacement.
  • Lubricate the entire area of the spline that comes in contact with the ASA.
  • Apply the specified grease to the camshaft bushing as specified by the manufacturer.

6. Lubrication

  • Before performing lubrication procedures on the cam bushings and ASA, release the brakes to ensure sufficient lubrication.
  • To ensure that contaminants have been flushed, add fresh grease until new grease appears at the purge point at components that require lubrication.
  • Refer to the component and lubricant manufacturer’s specifications to confirm that the selected grease is compatible.
  • Inspect wheel end oil levels as specified by the manufacturer and add oil as directed.

Axle Beam Inspection

1. Cracks

  • Any cracks found on the axle tubing require that the axle be replaced.
  • Repair the crack if it’s located at a weld and there is not a risk for the crack to penetrate to the tube. Weld repairs should conform to TMC RP 728, Trailer Axle Maintenance.
  • Repairs at areas where brackets have been welded to the beam are allowed.

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