How to Align Trailer Wheels

by Adam Quinn

Ryan McVay/Digital Vision/Getty Images

If your trailer pulls to one side or weaves, the wheels may be misaligned. Trailer wheel alignment is crucial for towing your cargo safely, and for preventing trailer damage. The trailer's front axle should be aligned perpendicular to the direction of travel. A slight deviation will cause a noticeable effect in the trailer's handling. Most trailer alignment problems are caused by a damaged or worn leaf spring assembly, a bent wheel rim or low tire pressure. In many cases, adjusting or replacing the damaged part may fix the problem.

Assessment

Step 1

Connect the trailer tongue to your vehicle's hitch. Park the trailer on a level surface. Lower the trailer tongue jack stand to level the trailer, if necessary.

Step 2

Attach the fishing sinker to the end of the fishing line. Tie the fishing line to the bottom threads of your vehicle's tow hitch, allowing the sinker to hang. The fishing line and sinker should be hanging directly below the center of the trailer tongue ball hitch coupler. This will provide a plumb line for assessing your wheel alignment.

Step 3

Remove the hub caps on your trailer's wheels, if necessary. Screw an axle extension tube to the center spindle on either wheel.

Step 4

Measure and note the distance between the plumb line and the tip of the axle extension tubes on either wheel. Compare the distances from the plumb line to the right wheel and from the plumb line to the left wheel. If the distances deviate by more than 1/8 inch, your wheels are likely misaligned.

Step 5

Measure and note the distance between the front wheel and rear wheel on either side of the trailer, if your trailer has a second axle. Compare the distances between the right wheels and the left wheels. If the distances deviate by more than 1/8 inch, then the rear axle is out of alignment with the front axle.

Alignment

Step 1

Inspect the leaf spring assembly, which suspends and protects your axles. Replace the U-bolts and retainer brackets that hold the springs to the axle, if they appear loose or cracked. If cracked or bent, replace the front and rear shackle brackets that secure the leaf spring ends to the undercarriage. Replace the leaf springs if they are sagging, cracked or twisted.

Step 2

Inspect the conditions of the wheels and tires. A bent wheel rim, low tire pressure or worn treads may interfere with the trailer's handling. Depending on the extent of the damage, a bent wheel rim may require professional attention, and possibly replacement.