Ready to Roll: Pre-Season Combine Prep

Shorter days and cooler nights mean it’s nearly time to pull the combine out of the shed and prepare for harvest. While it can be tempting to start as quickly as possible, building in a few days pre-harvest to thoroughly inspect your machine can save downtime and expense later — when you may not have the time to spare. 

“My theory has always been: An ounce of prevention is worth a pound of cure,” said Jake Koehn, technician at Diamond K Combine Repair in Lakin, Kansas. “You can do the repairs in the shop, in a controlled environment, where it’s faster and cheaper than if you’re out in the field. It’s less about, ‘Can I make this stretch one more year?’ and more about, ‘How could this cause something else to go out if I don’t pay attention now?’”

Be Sure About Safety

Safety measures such as the seat belt, brakes, and fire extinguisher are sometimes overlooked, but are critical. Taking time to make sure everything works as it should can prevent serious injury or even death. Accidents can happen quickly, and being prepared when you’re out in the field is necessary. 

Have a well-stocked first aid kit in the combine and other farm vehicles. The National Education Center for Agricultural Safety has farm first aid kits that include large scissors to cut through heavy clothing, bandages of all sizes, a thermal blanket, eye wash, instant cold compresses, and more. These kits can be purchased directly from them, or you could assemble your own.

Also consider the seat belt, brakes, and fire extinguisher.

“My uncle had a situation where a belt shredded while he was driving the combine, and it hit a wiring harness just right to where it set the parking brake on a dime,” Koehn related. “He’d been running about six and a half miles per hour and it locked up solid. The steering wheel stopped him from going through the windshield, likely saving his life, but he bruised some ribs pretty badly.

“Don’t underestimate the safety components.”

Take a Look at the Tires

Assess tire condition as well as tire inflation pressure. If your machine runs duals, make sure all four tires are within 1–2 psi of each other. 

“If tire pressures are unequal, you will place uneven loads across the wheels and tires, which is especially problematic when grain tanks are full or ground conditions are uneven,” said Kevin Forth, Fendt Ideal senior marketing manager. 

Travis Lamb, field technician for Titan International, said all of the company’s ag specialists carry scales with them to weigh equipment on site and make inflation recommendations. 

“The whole theory behind tires is knowing what the axle load is, and then setting inflation pressure to minimize ground bearing pressure — compaction,” he said. “If you don’t know the actual load weight, you don’t know what pressure you need and you’re just guessing at that point.” 

Using low sidewall (LSW)  tires on a combine could also be a benefit, depending on your conditions.

“There’s something to be said about getting into the field earlier with more flotation at harvest,” said Scott Sloan, global ag/LSW product manager for Titan International. “We’re seeing the trend to super singles from not only a compaction standpoint but also for ride comfort.”

If your combine has tracks, double-check oil levels on all components to be sure they are properly lubricated.

Check Common Wear Points

Koehn begins combine inspections by letting the machine run for an hour. He removes the shields and walks around the entire machine, listening for anything that seems unusual. 

Examine belts and covers for separation, missing chunks, burned streaks, and grooves in their sides, all of which can be symptoms of a misadjusted belt or worn pulley, or something more serious, like an impending bearing or bushing failure. 

“A trick to avoid downtime during the season is to use an infrared thermometer to spot bearings that are running warm and directing attention to them before trouble develops,” Forth said. Besides checking their temperature, Koehn also uses a pry bar to check for play in bearings that shouldn’t be there. 

Finish your walk-around by generally inspecting the combine’s frame, cleaning shoe, and feeder house shoe for cracks.

Look at the Cleaning Shoe

Remove the chaffer and the sieves and look for general wear, particularly in the front half of the chaffer, where the highest amount of grain and residue flows in from the separator.

Koehn advises checking any variable sheaves. “I’ve seen variable sheaves that aren’t greased properly start wearing into the shaft,” he said. “And I’ve seen a lot of guys having to replace the whole shaft because they weren’t paying attention to the sheaves.”

Check assembly bolts for looseness, and be sure to tighten the torque to what the owner’s manual recommends. Look for bent or missing fingers, and notice where the chaffer and sieve rods operate in the frame, watching for elongated holes. Examine the deflector flaps and high-crop dividers to see whether they are missing or damaged.

Inspect the shoe augers, looking at their flighting for wear and whether they have been bent. Confirm that augers are not bowed, as this greatly diminishes their ability to move grain.

Examine the cleaning fan, scrutinizing the vanes for damage, which can happen when the fan ingests grain or foreign objects. This can also be an indication of problems elsewhere in the shoe. Finish looking at the cleaning shoe area by examining the shaker arm assembly and bushings. Loose bearings, bent arms, or worn bushings can create vibration, leading to chaffer and sieve damage.

Header Help

“Don’t forget your headers, which are often overlooked for maintenance,” Forth said. 

Check all gearboxes for oil, make sure cutting devices have proper clearance and are sharp, and grease everything. 

“Your combine hooks to another piece of equipment, and you have to pay attention to that connection,” Koehn added. “Cleanliness is a lot more key than most people understand, and it does make a difference.”

Clean your header regularly during the season, especially if rain is in the forecast, and thoroughly post-harvest. 

A well-maintained feeder house is critical to smoothly deliver crop to the threshing rotor. Be sure to examine the slats for evidence of wear or bending, as well as the feeder house chains and sprockets. Sagging chains accelerate wear, leading to chains jumping on sprockets.

The feeder house floor is a high-wear item that needs attention: Look for holes that foreign objects may have created. Also, check the drum arm bearings for smooth operation. Examine the drive belt’s entire length for cracks, missing pieces, burned spots, and belt separation.

Concentrate on Concaves

Generally, farmers do a good job inspecting the rotor or cylinder. Where preseason inspections fail is in examining concave elements for rounded or bent bars, missing wires, foreign objects, or residue buildup. Remove and thoroughly clean the concave panels, and ensure they are level when reinstalled. Check that the seals on covers are intact, and inspect the front beater plates for wear.

Also take time to inspect the induction (rotor) cone, making sure all its hardware is intact and not bent or worn. Examine the rotor impeller’s leading edges for wear or cracks. The rotor and rasp bars require scrutiny to detect excessive wear, missing surfacing, and serrations damage; all can decrease grain quality, slow down threshing, and boost threshing power requirements. Worn rasp bars are a particular problem and can best be measured with an indicator you can get from your dealer.

Understand the Unload Auger and Elevators

“I always watch the unload auger pretty closely,” Koehn said. “At the end of the day, you can separate all the grain you want, but if you can’t unload it, it won’t do you much good.”

Check the flighting on all augers, as wear can sometimes leave sharp edges, leading to grain damager. Pay special attention to the bearings on the unload auger gearboxes, as they are much easier to replace before the season starts.

“The problem with the bearings in a gearbox on an unload auger,” Koehn noted,” is that they always seem to go out when your tank is full, and you end up losing a lot of profits because you always spill crop on the ground when you’re removing the failed part.”

Improperly functioning elevators keep grain from even making it to the bin. Remove the drive belts from both grain elevators and rotate the chain assembly. This allows you to find worn or missing paddles and sagging chains. Next, check the chain tension and adjust it, as needed. Recheck the tension daily during harvest.

Adjust the tension on the elevator, so the paddles don’t sag backward during operation, called “backlegging,” when grain cascades back down the elevator. This limits the capacity and causes the cleaning shoe to overload.

Scan the Separator

Look over the separation area’s three key components – the directional vanes, the separation tines or bars, and the separator grates – for wear and damage; you’re most likely to notice wear in the front or back row of tines or bars. Be sure to measure those, as a visual inspection doesn’t always reveal wear. Take time to check for broken or missing mounting hardware. Also, look over the separator’s grates for damage an ingested foreign object may have inflicted. Finally, confirm that bolts are secure.

Review the Residue Management System

Review all key elements of the residue management system, whether it is a simple spreader or a more complicated residue chopper.

Begin by looking at the discharge beater that feeds the residue from the back of the rotor to the spreader or chopper. Look for excessive wear and damage from objects exiting the combine. Wear to this beater can cause plugging of the separator due to product not being properly removed from the rotor.

In tailboard vanes and spreader elements, the key is to look for wear or damage, since that compromises distribution. Hand-rotate traditional spreader to ensure they operate smoothly, and check for wear on the distribution vanes.

In more complicated residue chopping systems, be sure to examine hinge points for stress cracks; they indicate excessive vibration or imbalanced operation. Balance is vital to chopper life. Missing knives or failure to replace knives in matched sets can create vibration that could cause additional damage.

Keep a sharp eye for worn knives – they do a poor job of sizing residue. Worn knives can also cause chopper operation to drag, consuming more horsepower. If knives need replacing, do so in sets; otherwise the chopper is thrown out of balance. Finish your inspection by scrutinizing the unit’s mounting hinge points for stress cracks, and the rotor bearings for smooth operation.

While you’re at the back of your machine, take time to jack up the combine and see whether there’s any play in the tie rods or wheel spindles.

Especially in combines with bigger back tires, “You can burn through tie rods a lot faster when you’re turning with a full load of grain,” Koehn noted. “It’s not a fun ride to lose one of those going down the road, all of a sudden.”

Mind Your Monitor

This is a good time to load new maps and information into your monitor, and delete old data. Setting your current fields before the rush of harvest saves time and frustration. 

Mass flow sensor calibration takes a little time, but it’s vital for ensuring accurate yield measurements. The process usually involves harvesting two to six small loads (3,000–5,000 pounds, depending on your manufacturer’s specifications) and measuring each load’s scale weight. The number of loads will compensate for varying yields expected across a field during harvest. Crop type, moisture content, and test weight can affect mass flow sensor readings, so consider calibrating separately under those circumstances.