Used Grain Auger Inspection Checklist: What to Check Before You Buy

Buying used · 8 min read

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A used grain auger looks like about the simplest machine on the farm: a tube, a screw inside it, and a motor or PTO shaft to turn it. That simplicity is part of the appeal, and part of the trap. An auger moves thousands of bushels through a steel tube every season, and grain is abrasive. Flighting wears thin, tubes wear through, and bearings go dry — none of which shows up in a listing photo.

The tube: straight, round, and solid

Walk the full length of the tube and sight down it from each end, the way you would sight a fence line. A tube that is bent, kinked, or bowed will bind the flighting inside it, and a bind under load snaps shafts and burns up gearboxes. Dents matter most where the flighting passes close to the tube wall; a dent that pinches the flighting is a real problem, while a shallow dent in an exposed section usually is not.

Check the tube wall itself, especially on the bottom side where grain rides. Grain wears steel from the inside out, so a tube can look fine outside and be paper-thin along the bottom. Press firmly along the underside for soft spots or flexing steel, especially at the joints between tube sections and the discharge end, where grain changes direction and wear concentrates. Several welded patches mean the tube has been wearing through for a while, and the next thin spot is already forming somewhere you cannot see.

Flighting: the part that actually does the work

Flighting is the screw inside the tube, and the first thing to wear out. You cannot always see its full length, but you can learn a lot from the ends and any inspection opening.

At the intake end, look at the exposed flighting. New flighting has a square, full-height edge. Worn flighting loses height first, then the edge goes thin and knife-like. If the flighting at the intake is worn to a thin edge, the flighting inside the tube has had the same grain running through it and is in similar shape. Sight down the tube from the discharge end with a light if you can; you want flighting uniform in height all the way down, not sections gone short or wavy.

Ask the seller to turn the auger by hand with the power off. It should turn smoothly all the way around, with no catching, grinding, or tight spots. A tight spot in one part of the rotation usually means a bent tube, a bent shaft, or flighting rubbing the tube wall — and any of those only gets worse under load.

Bearings: the quiet killers

Bearings are where a used auger deal goes bad quietly. A dry or worn bearing will not show in a photo, and it can seize mid-harvest and take the shaft with it.

Find every bearing: the intake-end bearing, the discharge-end bearing, and every hanger bearing along the tube. Each should turn smoothly by hand, with no grinding, roughness, or play. Grab the shaft at each bearing and try to move it up and down and side to side; any noticeable play means the bearing is worn, and a worn bearing lets the flighting rub the tube, which wears both.

Check whether the bearings take grease. Pump a shot into each zerk: grease coming out around a blown seal instead of into the bearing means the seal has failed and the bearing has likely run dry. Missing or painted-over zerks are a sign the machine has not been greased on a schedule.

On longer augers, hanger bearings support the shaft mid-span, and when one fails, the shaft sags, the flighting drags, and the tube wears fast. If the seller cannot say when they were last replaced, assume they need a close look.

Intake: hopper, cage, and guarding

The intake is where grain — and everything else — enters the auger, so it takes abuse. Check the hopper for dents, cracks, and rust-through, especially along the bottom edge and where it bolts to the tube.

Look at the intake cage or guard. Guarding around the intake flighting is a safety item, not a cosmetic one: it keeps hands, boots, and loose clothing out of exposed flighting. A missing, bent, or jury-rigged intake guard is a deal-breaker until it is properly replaced — this is the part of the machine that injures people. Check that the guard is complete, solidly mounted, and sized so flighting is not reachable through it.

Check the intake flighting for damage from foreign objects. Rocks, frozen lumps, and metal leave nicks and bent edges on the first few flights. A few nicks are normal wear; flighting folded over or missing chunks means the auger has swallowed something hard, and the shock may have traveled up the shaft to the bearings and gearbox.

Drive: motor, gearbox, PTO, and belts

However the auger is driven, test the whole drive, not just the part that spins. On an electric-motor auger, check for a sound mounting and clean connection — no frayed wiring, no cracked junction box, no motor that hums but will not start under load. On a belt-driven machine, belts should sit straight in their grooves with no cracking or fraying, and pulleys should run true without wobble; a missing belt guard is a safety problem, not a detail.

On a PTO-driven auger, check for an intact guard, U-joints with no play, and a shaft that telescopes freely without binding. Check gearbox oil if it has one — milky oil means water has gotten in, and oil full of metal means something inside is coming apart. On a hydraulic drive, run it through its full range for smooth, steady speed, and check hoses for chafing and leaks.

Undercarriage, wheels, and transport

Check the undercarriage frame for cracks, especially at the welds where the axle meets the frame and where the lift mechanism attaches. The lift cable or winch should be free of frays, kinks, and rust, and the winch should raise and lower the auger smoothly without slipping.

Check the tires for dry rot and cracking sidewalls — auger tires often rot before they wear out, since the machine sits most of the year. Check wheel bearings by jacking a wheel and spinning it; it should turn freely with no grinding or wobble. Look at the hitch and safety chain, confirm the lights work if it travels on public roads, and cycle any mover kit mechanism.

The live test: run grain through it

A visual inspection only goes so far. If the seller will let you, run grain through it — even a short run tells you things looking will not.

Listen first. A healthy auger has a steady, even sound. Grinding, knocking, or a rhythmic thump matching the shaft rotation points to a bearing, a bent shaft, or flighting rubbing the tube. Watch the discharge: grain should flow steadily with no surging. Surging usually means worn flighting clearance — grain slipping back instead of moving forward — and it gets worse as the load increases.

Watch the intake while it runs. Grain should feed evenly without the flighting choking or the motor bogging; if the motor or PTO labors hard on a light load, something is binding inside. Check the bearings again after the run: a bearing that comes out hot has a problem a cold check missed. Look for grain leaking from tube joints or the discharge — a leak at a joint means a worn seal or cracked seam.

Records and questions to ask

Ask what the auger moved and how it was stored. An auger that ran fertilizer or treated seed wears faster than one that ran only clean grain, and fertilizer is corrosive to the tube and flighting. Ask whether it was stored inside or outside and cleaned out between seasons — grain left in a tube over winter holds moisture against steel and speeds corrosion from the inside.

Ask about bearing and flighting replacement history and any tube sections replaced. A seller who can answer those questions has maintained the machine; a seller who cannot is telling you something too. Ask how old the tires are, and whether the auger has ever been dropped or tipped during transport — a tipped auger often has a bent tube that looks straight until you sight down it.

The short version

Sight the tube for straightness and thin spots. Check flighting height and edge thickness at both ends. Test every bearing for play, roughness, and grease. Inspect the intake guard — missing guarding is a walk-away issue until fixed. Test the full drive, check the undercarriage and tires, and whenever possible, run grain through it and listen. An auger that passes will do its job for years. One that fails several checks is telling you where your harvest season will go sideways.