How to Check the Alignment of a Tandem Trailerby Adam Quinn
If your tandem trailer pulls to one side, you'll need to check the axle alignment to ensure the trailer is safe to haul loads. Trailer alignment requires precision measurement to establish correct calibration of the right and left sets of wheels. Trailer alignment recommendations allow little room for error; incorrect calibration can greatly increase the risk of accidents occurring. Improper alignment may also result in axle damage while hauling heavy loads. Check your tandem trailer for proper axle alignment to reduce accident risk, and guard against cargo damage.
Park on a level surface. Connect the trailer tongue to your vehicle's hitch. Lower the trailer tongue jack stand to level the trailer, if necessary.
Tie the fishing sinker to the end of the twine. Tie the twine to the bottom threads of your vehicle's trailer hitch ball, letting the fishing sinker hang down. The twine should be suspended directly below the center of the trailer tongue's hitch ball coupler. This plumb line will be the trailer tongue reference point.
Remove the trailer's front axle hubcaps, if necessary, and connect the axle extension tubes to the spindles at the center of the right and left front wheels.
Measure and note the distance between the plumb line and each axle extension tube. Measure to the tip of each tube.
Attach axle extension tubes to the spindles at the center of the rear wheels. Measure and note the distance between the front and rear axles on either side of the trailer. Measure from the center of the extensions tubes.
Compare the measurements from the plumb line to the right and left sides of the front axle. If the distances deviate from each other by more than the manufacturer's specifications, the front axle may need adjustment. If you do not have an owner's manual, make sure the deviation between the right and left side of the front axle is less than 1/8 inch.
Compare the measurements between the front and rear axles of the right side versus the left side. If the distances deviate from each by more than the manufacturer's specifications, the rear axle may need adjustment in relation to the front axle. If you do not have a manual, make sure the deviation is less than 1/8 inch.
Repeat the alignment check procedure once you or a mechanic have performed the necessary adjustments.
- If your trailer has a kingpin hitch located beneath the front end of the trailer body, use a kingpin extension tool for the plumb line reference.
- A second person may be necessary to perform these measurements correctly.
Things You'll Need
- 4 axle extension tubes
- Fishing sinker
- Tape measure
- Trailer owner's manual
Adam Quinn has been writing since 2008. His articles have appeared in the "Journal of Humanistic Psychology." Quinn holds a Master of Social Work from the University of Washington in Seattle, where his focus of study was counseling combat veterans with post-traumatic stress disorder.