Over time, a hanger can develop fatigue cracks, especially if it has been operating under severe operating conditions. Here is your guide to repairing cracked hangers.

There is often an underlining cause, such as loose pivot bolt, deteriorated pivot bushes, faulty shock absorbers, or bad driving habits that should be addressed before completing the repair.

Image: Hendrickson

A repair kit is available for Hendrickson hangers that includes a reinforced steel plate, along with instructions. This kit is designed for hangers that have minor fatigue cracks on the inboard side. QUIK-ALIGN pivot hardware and wear washers should also be purchased as required.

For hangers with cracks on the outboard side, severe cracking, or excessive wear, replacement is the ideal solution. However, in some circumstances the inboard side repair kit or the gouged hanger repair kit may be used, depending on location and severity of cracks and damage. New hangers may have the reinforcing plate installed at the same time to improve durability in severe conditions.

Follow these steps to replace your hangers and get everything working like new:

Support the axle to prevent it dropping and remove the pivot fasteners.
Lower suspension trailing arms away from hangers.
Discard used fasteners.
Clean area around crack(s) and prepare surface for welding the reinforcing plate.
Stop drill the crack(s) at start and finish.
Grind a V into the crack to prepare for the weld repair.
Repair crack with V-groove butt joint weld.
Grind the weld until it is level with hanger.
Install reinforcing plate into position.
Clamp plate in position, ensuring QUIK-ALIGN openings are horizontal within 1 mm.
Stitch weld the plate into position. Make 6 mm fillet welds 25 mm long with approximately 30 mm gaps around the outside of the plate.
Weld the inside of the plate at the QUIK-ALIGN opening to the hanger with a 6 mm fillet weld.
Check the inside of the hanger to ensure the surface will not be detrimental to wear washer durability. Clean, repair and linish as necessary.
Assemble the suspension trailing arms with new pivot hardware and wear washers. Ensure the eccentric flanged washer is outboard, with the square adjusting hole at the 12 o’clock position.
Tighten pivot bolt to around 100 Nm to hold in place until the alignment is completed.
Reassemble trailer and restore to normal operation.
Align trailer axle(s) to manufacturer’s specifications.
When axle is properly aligned, and at ride height, fully torque the QUIK-ALIGN bolts until the Torx head shears off, which is approximately 800 Nm.
After alignment, paint all affected areas to the trailer manufacturer’s specifications.
Recheck trailer components and operation of systems and return to service.

Regular trailer inspection is essential in identifying and rectifying any potential issues that may lead to stress cracking, such as loose pivot hardware.

These inspections help minimise repair costs and reduce unplanned downtime by catching problems early before they escalate into more significant issues.