Pre-Harvest Combine Inspection Checklist for Ohio and Indiana | Koenig Equipment

If you farm in southern Indiana or southern Ohio, wheat harvest is two to three weeks out. By the time you read this, somebody on the south end of Posey County or Switzerland County is probably already watching the calendar more closely than they would admit. Combines that ran clean last fall are sitting in the shed, full of last year's chaff, and the to-do list that you swore you'd handle in February is still waiting in the cab.

This is the post we wish every customer would read before they roll the combine out for the first cutting of wheat. None of it is glamorous. All of it saves hours, and in a bad year, it saves days. The goal here is to give you a practical walk-around you can do this week, before the field is dry and the elevator is calling.

Why mid-June, and not the night before

Wheat in southern Indiana typically starts coming off in the last week of June. South-central Ohio runs a few days behind that. Once it starts, you have a narrow window before grain quality drops, prices shift, and the next field opens up. A combine that breaks down on day one of wheat throws off the entire harvest calendar, because soybean and corn aren't going to wait for parts to ship.

Mid-June is the window where the service department can still take a same-week appointment. By July, every dealer in the region is in triage mode. Spending an hour this week looking at your combine is the cheapest insurance you can buy.

The other reason to look now is that some of the issues you find are things you genuinely can fix yourself. Belts, chains, bearings, sieves, sensors, electronics, software updates. The earlier you find them, the more likely the part is in stock at our parts counters rather than backordered through a supplier.

Start with last year's harvest data

Before you put hands on the machine, open Operations Center. The data from last year's run is the best diagnostic tool you have. Look at your machine reports for the last week of operation. Where did you see fault codes that you cleared and forgot about? Where did the grain loss numbers creep up at the end of the day? Were the sieve and concave settings drifting away from defaults?

A combine that finished last fall with intermittent header height sensor faults is a combine that will fault again in the first hour of wheat unless you address it. Operations Center has the history.

If you do not have last year's data synced and accessible, that itself is the first thing to fix. Make sure your machine and office are talking, that your fields are current, that any new field boundaries from spring planting are loaded. A combine that loses connectivity in the middle of a wheat field is not the place to troubleshoot Data Sync.

The header and feeder house

Most pre-harvest problems we see at the service door come from the header and the feeder house. This is also where the wheat-versus-soybean-versus-corn calculus shows up the most, because what you ran last in fall is rarely what you start with in summer.

Walk-around items for the header:

• Sickle and guards. Pull the head, lay it flat, and look at every guard and every sickle section. Replace any that are rounded, cracked, or chipped. A guard at the wrong height drags grain heads onto the deck and shells them before the reel touches them.
• Reel timing and bat condition. Check that the reel is centered, that the bats are straight, and that the rubber or plastic fingers are intact. Bent bats throw grain forward in patterns that look exactly like a feeding problem.
• Cross auger and finger pickups. Spin the auger by hand. Anything that grabs, ticks, or wobbles is a bearing or a finger that will fail mid-field.
• Header height sensors. Calibrate them. Especially if you are switching to a small-grain header this is the first calibration you want clean, because uneven header height in wheat shows up as crooked stubble and missed grain immediately.

For the feeder house:

• Conveyor chain tension and slats. Run the feeder by hand if you can. Check every slat for cracks and every cross member for wear. Chain that slipped a tooth at the end of corn is chain that will slip again.
• Drum. Look for bent drum fingers and worn paddles. Wheat is forgiving up to a point, but uneven feed shows up as uneven threshing later.
• Header-to-feeder-house seal and dust shields. A worn seal lets fines into the cab and into the engine bay. Replace any cracked rubber now.

Threshing and separation: rotor, concave, and chaffer

This is the part of the combine that customers most often skip in the pre-season because the access is harder and the visual feedback is less obvious. It is also the part of the combine that, when it fails or comes out of adjustment, costs the most grain in the field.

For the rotor and concaves:

• Concave condition. Open the concave doors and inspect the bars. Wheat is harder on concaves than corn because the grain is small and the trash flow is dense. If you ran a corn concave at the end of last fall, this is the moment to decide whether you are switching to a small wire concave for wheat, or running your variable-stream concave through a settings refresh.
• Rotor wear strips. Look for cracked or thinned strips. Replace anything questionable. A worn strip lets the rotor scuff the inside of the case and shave metal into your grain tank, and that is a conversation no one wants to have at the elevator.
• Threshing element bolts. Tighten every accessible bolt. Vibration loosens fasteners across a season, and a missing element at full RPM can take out the rotor housing.

For separation:

• Beater grates. Clean them and check for cracks. Carry-over from last season is usually visible as a thick mat of stalk fiber that needs to come off before you start.
• Chopper and spreader knives. If you chop residue, every knife matters. Dull or missing knives cost fuel and throw uneven residue, which kills planter performance the following spring.
  
  

The cleaning shoe

The cleaning shoe is where pre-harvest setup pays off the fastest in wheat. Small grain falls through the sieves differently than corn or beans, and a shoe that was set for corn at the end of last fall will dump grain over the back in the first round of wheat if you do not reset it.

What to check:

• Chaffer and sieve condition. Look at every louver. Bent louvers do not close fully, and a sieve that does not close throws clean grain over the back.
• Pre-cleaner. Clean any buildup. Pre-cleaners that load with last year's chaff cannot do their job, and the shoe runs dirtier than it should from the first pass.
• Cleaning fan. Inspect the impeller for bent blades and the fan housing for cracks. If you have variable speed control through the Gen 4 display, run the fan through its range with the combine running to confirm the response curve is clean.
• Settings. Reset to factory defaults for wheat, then make field-by-field adjustments from there. Starting from last fall's corn settings is the most common reason a customer calls us in a panic on day one of wheat.

Engine, drivetrain, and hydraulics

Treat this section the way you treat the tractor section of pre-season prep. The combine is, before anything else, a heavy machine that runs on schedule.

The fast list:

• Pull every air filter and inspect or replace. Wheat dust is finer and harder on filters than corn dust.
• Check engine oil and coolant levels, and check the date on the last sample. If you sample your oil annually (and you should), the pre-harvest pull is the right one.
• Inspect all coolant and intake hoses for cracks and weeping.
• Walk every belt. Replace anything cracked, glazed, or visibly stretched.
• Drain the fuel-water separator. Wheat dust gets into everything, including the fuel side, if a cap or breather is compromised.
• Check hydraulic oil level and color. Cloudy hydraulic oil is a sign of water intrusion that you want resolved before harvest, not during it.
• Walk the drivetrain. Final drive and steering axle, look for leaks. Loose lug nuts get tight quick in our shop.

Electronics, sensors, and software

Modern combines are field computers with a header attached. The pre-harvest list here is short but critical.

• Software updates. Check that your display and combine controllers are on the current John Deere software release. Updates released in the May-June window often include harvest-relevant fixes. We have an updated list of current releases at the parts counter and can flash anything that needs to be brought current.
• Yield monitor calibration. Pull last year's calibration file, review it, and plan to recalibrate on the first 5 to 10 loads of wheat. Calibration drifts. Recalibrating in the first hour is faster than fixing a season of bad yield data.
• Moisture sensor. Inspect the sensor face for buildup and replace any cracked dust shields. A moisture sensor that reads incorrectly throws off both your dryer plan and your yield map.
• Header height and tilt sensors. Calibrate after any service work and verify with the head on the ground.
• Combine Advisor. If you run Combine Advisor, verify that the camera lens is clean and that the lighting in the clean grain elevator is functioning. Anyone who ran the system last year already knows how quickly a dirty lens disables the auto-adjust functions.

DIY versus service department: the honest version

Here is the part we owe you. Not every check on this list is a Saturday afternoon job, and that is fine. The DIY-friendly items are the ones where the failure mode is visible and the parts are bolt-on: filters, belts, sieves, header sickle sections, concave inspection, chain adjustment, exterior cleaning, fluid checks.

The items where it is usually faster and cheaper to bring it in: rotor strip replacement, drive system internal inspection, complex hydraulic diagnostics, software flashes, full yield monitor calibration with our test loads, and any electrical fault that does not clear after a basic reset.

If your combine is past 1,500 hours, a pre-season service department inspection is the single highest-ROI thing you can buy in June. Our service teams across our locations from Indianapolis and Greensburg through Lebanon and Bloomington and into the Ohio side are set up for exactly this window. The earlier you call, the better the appointment.

Schedule Pre-Harvest Combine Service

A quick word on parts

Our parts counters are stocked heavily for harvest by the second week of June, but the high-velocity wear parts (sickle sections, guards, concave bars, fan belts, header chains) move fast once the season opens. If your inspection turns up anything, ordering this week is the difference between a same-day pickup and a three-day wait. The May 14, 2025 John Deere Parts Catalog overview is still a useful reference for navigating the catalog.

The 30-minute walk-around: a condensed version

If you only have 30 minutes between everything else this week, do this:

1. Pull the engine air filter and look at it. 2. Walk every belt with the combine running, then shut it off and check tension. 3. Open the rotor and look at the strips and the concave bars. 4. Open the shoe and look at the chaffer and sieve. 5. Spin the cross auger and the reel by hand. 6. Open Operations Center and check for any unresolved fault history from last fall. 7. Make a parts list and call us.

The combines that finish harvest first are not the ones that ran the fastest. They are the ones that started the day clean, calibrated, and ready, and stayed in the field instead of in the shop. Mid-June is where that decision gets made.

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