How to Repair Worn Hangers

Hangers are not an item that normally wear. However, they may become gouged or worn from a loose pivot bolt or wear washers that have worn through – this guide takes you through a step by step process on how to repair worn hangers.

Any hanger wear or gouging will need closer inspection to determine the repair needed. Hanger wear less than 1 mm deep will usually be acceptable, provided there are no cracks or sharp ridges that cannot be smoothed out.

Hendrickson has developed repair kits to restore considerably gouged or worn hangers. Each kit includes two adaptors, bolt, nut, and washers to repair one hanger.

However, the hanger should be replaced if the damage is severe. Additional QUIK-ALIGN pivot hardware and wear washers should be purchased as required.

To do so, follow these steps to safely replace your hangers.

1. Support axle to prevent it dropping and remove the pivot fasteners.
2. Lower suspension trailing arms away from hangers.
3. Discard used fasteners and wear washers.
4. Remove hanger alignment collar by grinding off the weld. Do not use a cutting torch because the heat will alter the strength of the hanger. Ensure that no hanger material is removed when removing the alignment collar.
5. Cut pivot bolt openings in hanger to suit step in repair adaptors. Openings must be level horizontally and approximately 78 x 58 mm in size.
6. Install the two new QUIK-ALIGN hanger repair adaptors onto the hanger. Position the adaptor with the alignment guides on the outboard side of the hanger. For the wide bush suspension guides, ensure the stamped “TOP” marking is facing upwards. The narrow bush adaptors are symmetrical, so they can be fitted in any orientation.
7. Clamp adaptors in place, ensuring they are level horizontally and as far forward as possible.
8. Measure the distance of the adaptors from the bottom of the hanger to ensure they are level within 1 mm.
9. Weld the adaptors to the hangers with complete all-round 5 mm fillet welds.
10. Assemble suspension trailing arms with new QUIK-ALIGN pivot hardware and wear washers. Ensure the eccentric flanged washer is outboard, with the square adjusting hole at the 12 o’clock position.
11. Tighten pivot bolt to around 100 Nm to hold in place until the alignment is completed.
12. Reassembly trailer and align trailer axle(s) to manufacturer’s specifications.
13. When axle is properly aligned and at ride height, fully torque the wide bush QUIK-ALIGN repair kit 1”-14 UNS bolt to 850 Nm. Torque any standard and narrow bush pivot bolts until the Torx head shears off, which is approximately 800 Nm.
14. After alignment, paint all affected areas to the trailer manufacturer’s specifications.
15. Recheck trailer components and operation of systems and return to service.

Although it is possible to repair damage like this, the best approach is to prevent the damage from occurring in the first place.

Regularly inspect the pivot hardware to ensure that it is properly torqued and replace any wear washers that have worn through.

Taking these preventive measures can help avoid costly repairs and downtime.