Preharvest corn head checklist: Guidelines to significantly reduce yield loss and in-season breakdowns.

“As a piece of equipment, university research* indicates sixty-percent of yield loss at harvest is credited to the “corn head,” says Fenton, Iowa, farmer and Dragotec President Dennis Bollig. “But it’s through the individual row units – component-by-component – where that loss actually occurs.”

“The devil is in the details,” Bollig says. “Taking time to thoughtfully examine even the smallest parts of your corn head before harvest can significantly minimize overall loss and deliver greater harvest success.”

He suggests the following pre-harvest checklist as a guide for reducing corn head yield loss and untimely equipment breakdowns:

Snoot Dividers: From the side of the corn head, look down the snoot tips and make sure they are all level with each other. “You want uniformity across the head for accurate header height function and position, this is especially important when harvesting down corn.

Deck Plates: Producers with hydraulic deck plates should look for extra wear in linkage at every one of the many pivot points, Bollig says. “And it’s crucial to measure and recalibrate the gap in each row for uniformity. Even just 1/8th-inch difference can result in yield loss, and a 1/4” to 1/2" gap difference is not uncommon today, especially with many acres of wear.” Drago deck plates adjust automatically to stalk widths, row by individual row, and eliminate the worry of proper gap spacing during harvest.

Knife Rollers: Pay extra attention to wear within the first 1-3 inches of your knife rollers, Bollig notes. Despite their overall length, he says that’s where most corn head brands process stalks, compared to Drago’s design that allows stalk processing to move back their full length into the corn head. “If knife rollers are not pulling plants down as they should, you get more “stripping” vs the pulling down action, delivering more plant material into the combine and yield loss out the back.” Drive chains: Inspect drive chains and tensions. Bollig recommends removing chains and laying them on a table – moving links in and out to see movement to check wear on roller pins to avoid in-season breakage. “If you’re near the end on tension adjustments, consider replacing them,” Bollig says. “They will break when you need them most.” Gear-driven drives, such as those found on Drago corn head last through the life of the corn head. Gathering chains: Like drive chains, inspect this critical component for wear at the pins and readjust for proper tension. Loose chains will accelerate wear and eventually throw off their sprockets. A common culprit of loose chains are open spring tensioner designs that allow dirt and debris to build up on the spring, decreasing the chain tension. Heads that have this design should be blown off before the season starts and multiple times in the season to prevent loose chains and increase chain life.

Auger: Check the flighting for bends and make sure the entire auger is running true. Bollig says tree limbs, rocks and other solid debris can be picked up and damage the auger, which then impacts wear pattern in the auger trough. He says to especially note overall trough wear near the feeder housing in the middle of the auger where most of the plant material is processed. “Holes will actually wear through the trough on corn head brands with thinner steel.”

Gear boxes: Check fluid levels and look for any signs of leakage from a bad seal. Any issues now may result in serious problems by end of the season. “And it’s always good to rotate knife rollers and choppers back and forth to see how much play there is in the gear box of each row unit,” Bollig adds. “Too much “slop” between gears suggests they aren’t meshing properly, which not only means wear is accelerating, but may be a sign the corn head itself may need replacing.” Drago gear boxes are more precise than any other brand for extended wear and durability.

Lubrication: Check zerks and make sure they are taking grease – listening or watching for grease to emerge from around the seal while filling.

Bollig says producers today are increasingly demanding more from their corn heads. “We’re asking them to process more acres than ever before. Twenty years ago, we were putting 50-100 hours on our corn heads compared the 150-200 hours or more we run today.”

“What this means is that we should be checking corn head components during the season – as well as pre-season – to avoid unnecessary yield loss,” he notes. “Durability and reliability is more important than ever.”

<sup>*Hanna, H. Mark, “Profitable Corn Harvesting” (2008). Agriculture and Environment Extension Publications. 203. [https://lib.dr.iastate.edu/extension_ag_pubs/203](https://lib.dr.iastate.edu/extension_ag_pubs/203)</sup>