Trailer Landing Gear Failure: Diagnosing Crank & Pad Wear

Gearbox wear is the number one culprit. The internal gears strip or the shear pin gives out from years of cranking without grease, or from someone forcing the handle when the legs were already binding on something else. Once the gearbox teeth round off, you get that familiar "crank spins but legs don't move" feeling.

Leg binding happens when the inner leg (the part that telescopes) gets bent from a hard drop, side-loaded during a bad coupling, or just rusted solid inside the outer sleeve from lack of lube. A bent leg will crank hard in one direction and bind up tight before it's fully extended or retracted.

Foot pad damage is the quiet killer. A cracked, bent, or undersized pad sinks into soft asphalt or gravel under load, which torques the whole leg sideways and transfers stress right back into the gearbox and crank handle. A lot of "gearbox failures" start as a pad that gave up a year earlier.

Don't wait for the legs to freeze solid. Watch for these early signs during pre-trip or at the yard:

• Hard cranking that's gotten progressively worse over a few weeks, not just cold-weather stiffness
• Grinding or clicking from the gearbox housing when you turn the handle
• Uneven leg extension — one side touches down before the other
• Visible lean in the trailer when the legs are fully down and the brakes are set
• Rust streaks or bare metal showing through where grease should be holding
• Bent or cracked foot pads, especially on the inside edge where ground pressure concentrates
• Play or wobble in the leg where it bolts to the trailer frame

Any one of these on its own is worth a closer look. Two or more together means don't trust that landing gear with a loaded trailer until it's inspected properly.

Pop the gearbox cover or access panel if your unit has one, and look for grease that's turned black, gritty, or dried out completely — that's the first sign the box has been running dry. Dry gears wear fast and start shedding metal shavings, which you'll feel as grinding before you ever see it.

Check the shear pin if your gearbox uses one — it's designed to snap before the gears do when someone over-cranks against a bind. A sheared pin with otherwise good gears is a cheap fix. A stripped internal gear means the whole gearbox assembly needs replacing — per OEM spec for your landing gear manufacturer, since gearboxes aren't universal across brands.

Spin the crank handle disconnected from the leg shaft if possible. If it's still rough or notchy with no load on it, the problem's inside the box, not downstream in the leg. If it turns smooth standalone but binds once connected, you're looking at a leg or shaft alignment problem instead.

With the trailer safely supported — never with your body under a leg that's under load — walk both legs top to bottom:

• Check the inner leg tube for visible bends, dents, or rust pitting along its length
• Confirm both legs extend and retract at the same rate when cranked together; a mismatch points to a bent leg or worn gear teeth on one side
• Inspect the foot pad for cracks, deformation, or a pad that's been welded/patched before
• Make sure the pad still swivels freely — a seized pivot pin transfers load wrong and bends pads fast
• Check mounting bolts and brackets where the leg attaches to the trailer frame for looseness or elongated bolt holes

A bent inner leg almost never gets better — it's a replacement item, not a straighten-and-reuse job. Trying to force a bent leg back into service is how you end up with a trailer drop at a customer dock.

Most landing gear failures are preventable with a grease gun and five minutes a month. Grease the gearbox zerk fitting and the leg tube's inner/outer sleeve contact points per OEM spec interval — don't stretch it out just because the handle still turns okay.

Use a grease rated for the temperature range you actually run in; a grease that gums up in winter cold will make the legs feel like they're seizing even when the gears are fine. Wipe off old, dirty grease buildup before adding new — packed-in grit acts like sandpaper on the gear teeth and leg tubes every time you crank.

If a trailer's been sitting unused for months, don't just crank it cold. Work the handle gently a few turns at a time, adding grease as you go, to loosen rust before it tears up the gearbox internals on a hard yank.