Fifth Wheel Maintenance: A Winter Checklist for Safe Coupling

The fifth wheel is the only connection between a tractor and its trailer. A poorly maintained fifth wheel can cause hard coupling, excessive slack, or in the worst case, a trailer separation. Winter salt, grit and ice make regular maintenance even more important.

Daily checks for drivers

• Look for cracks, bent parts and loose mounting bolts.
• Make sure the locking jaws close fully around the kingpin.
• Do a tug test after every coupling.
• Confirm the release handle is fully in the locked position.

Regular shop maintenance

1. Clean — remove old grease, salt and grit from the plate and locking mechanism.
2. Inspect — check jaws, locks and springs for wear. Measure for excessive slack.
3. Adjust — follow the manufacturer's procedure for lock adjustment.
4. Lubricate — apply the recommended grease to the top plate and moving parts.
5. Rebuild — replace worn jaws, springs and locks with a rebuild kit when needed.

Winter tips

• Grease more often in winter, because salt and slush wash grease away.
• Keep the release handle and pull rod free of ice.
• Consider low-temperature grease for the top plate.

Frequently asked questions

How often should a fifth wheel be greased?
Follow the manufacturer's schedule, and more often in winter or severe service.

What causes a fifth wheel to be hard to release?
Common causes are old grease, corrosion, ice in the mechanism, or the trailer pushing against the jaws. Clean, lubricate and check adjustment.

When does a fifth wheel need a rebuild kit?
When jaws, locks or springs are worn, or slack cannot be removed by adjustment.

Fifth wheel parts we carry

Shop the Automann Fifth Wheel Kit for Jost and Automann universal pin pullers, plus heavy-duty grease. Browse the Truck Parts collection.

Related guides: Truck Grease Guide · Gladhands and Trailer Air Lines

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