Used Fertilizer Spreader Inspection Checklist: What to Check Before You Buy

Buying used · 7 min read

← Back to blog

A used fertilizer spreader can be a solid buy — simple machine, no engine on most pull-types, and they don't move much. But dry fertilizer is abrasive and corrosive, and a spreader that's been run hard and put away wet will show it everywhere: rusted frames, worn spinners, and a rate controller that's lying to you. Here's what to check before money changes hands.

Start underneath: frame and corrosion

Fertilizer dust gets into everything, and it eats steel. Get under the machine and look at the frame rails, crossmembers, and the tongue. Surface rust is normal on a working spreader. Flaking rust that leaves pits, holes in crossmembers, or patched sections welded over thin metal are not. Tap suspect areas with a screwdriver handle — solid steel rings, rotten steel thuds.

Check where dissimilar materials meet: steel bolts through an aluminum or stainless hopper, U-bolts holding the axle, and anywhere a coating has chipped and stayed chipped. If the owner says the spreader gets washed after every use, the undercarriage should look like it. If it looks like it never saw a hose, assume the maintenance schedule matches.

The hopper: cracks, coating, and gates

Walk the inside of the hopper. Look for cracks in the welds, especially at the corners and around the gate openings. Hairline cracks grow. Next, the coating — many hoppers have a protective paint or polymer coating, and where fertilizer sat in it long enough to wear through the coating, the base metal starts thinning. Press on any soft spots; a hopper floor that's gone thin will flex.

Work the gate (or gates) through their full travel. They should move smoothly with no binding and close fully. A gate that won't close clean means uneven rates at the low end — which is exactly where rate accuracy matters most.

Conveyor belt or auger: the delivery system

Pull-type dry spreaders typically use a conveyor belt or an auger to meter material onto the spinners. Whichever it has, that's where your attention goes.

For a belt conveyor: run it and watch for tracking — a belt that wanders or squeals is misaligned or worn. Check the belt for fraying edges, cracks, and missing lacing. Look at the drive roller and idlers; they should be free of fertilizer buildup packed hard against them. Ask about belt tension adjustments — a belt at the end of its adjustment range is a belt that needs replacing.

For auger machines: check the flighting for wear. Worn flighting is thinner and shorter, which changes your metering. Check the auger bearings for play and listen for grinding when it turns.

The spinner assembly: where the pattern comes from

The spinner discs and fins decide your spread pattern, so worn ones cost you money every acre. Look at the spinner fins — they should be straight and complete. Bent, broken, or missing fins create an uneven pattern you can't fix with rate changes. Check the discs themselves for cracks and excessive wear.

Spin them by hand (engine off, hydraulics relieved) and check for play in the bearings. Then look at how the spinner height and position adjust. If the adjustment mechanisms are seized from corrosion, you're stuck with whatever pattern it throws.

Hydraulics and PTO

Check every hydraulic hose for cracking, chafing, and weeping at the fittings. Fertilizer dust and UV are brutal on rubber. Cycle the hydraulics and watch for smooth operation with no jerking. If the spreader runs spinners off a PTO or hydraulic motor, run it under load and listen. A hydraulic motor that whines or a PTO shaft with a torn guard are bargaining chips at best and deal-breakers at worst — PTO guards are a safety issue, full stop.

Running gear: tires, axles, brakes

Tires on a spreader often rot before they wear out, since the machine sits most of the year. Check the sidewalls for dry rot cracking and look at the date codes — tires over 8 years old are on borrowed time regardless of tread. Look for overloaded signs: bent rims, cracked hubs, or tires wearing unevenly because the axle is bent.

If it has brakes, they need to work. Surge and electric brakes on a machine that weighs several tons loaded are not optional. Test them.

Electronics: rate controller and scale system

This is where used spreaders quietly fail. A spreader with a bad rate controller will put on the wrong rate all season and never tell you. Power up the monitor and work through every menu. Check that the controller talks to the flow or speed sensors — with no GPS signal it should still read belt speed or gate position. If it throws error codes or can't find a sensor, price the replacement part before you negotiate, not after.

If it has a weigh system (load cells on the axle or tongue), compare its reading against a known weight — a full fuel barrel of water, for example, is roughly 430 pounds. If the scale reads meaningfully wrong, the rate controller built on it has been wrong too.

Check every harness connection for green corrosion. Fertilizer dust plus moisture turns connectors into science experiments. Wiggle them — intermittent connections are the hardest problems to find later.

The live test run

Don't buy a spreader you haven't seen run. Bring the seller some actual fertilizer or lime — even a partial load tells you things an empty run won't. Watch the full cycle: gate opens cleanly, conveyor or auger meters evenly, spinners come up to speed, pattern looks symmetrical. Listen for bearing noise under load that you couldn't hear empty.

Do a quick pattern sanity check if you can: lay a few tarps or catch pans behind the machine at set distances and run a pass. You don't need laboratory precision — you're looking for gross asymmetry, which tells you a spinner or fin problem instantly.

Records to ask for

Ask what you would for any used machine: maintenance records, belt or chain replacements, bearing work, and any controller or sensor replacements. Ask what rate it was typically set at and how often it was calibrated — a spreader that's never been calibrated in five years has been guessing for five years. And ask how it was stored. Inside, washed, and greased beats outside, dirty, and "it ran when I parked it" every time.