In the Shop: Finish the Fence

February 8, 2013 08:17 PM
In the Shop: Finish the Fence

You’re adept at prepping your planter for planting season. You understand the importance of properly adjusted disk openers, of centering closing wheels over the seed furrow and calibrating seed meters. But every year when your plants emerge you’re a few slats shy of the fabled "picket fence" final population everybody talks about.

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Inner disk opener scrapers wear narrower with age, allowing soil to disrupt seed depth in the furrow.

In many cases the missing slats can be traced to wear or problems with secondary components that don’t always get the attention that disk openers, gauge wheels and other primary parts earn.
Here are five components on planters that are often overlooked during annual maintenance:

  • Inner disk opener scrapers are mounted between the front edges of disk openers. If they are worn, moist dirt can build between the disk openers, spread their leading edges and eventually plug the openers so they can’t turn.

In dry soil, if there is too big of a gap between the scraper and the inside surfaces of the disk openers, it allows loose dirt to fall into the seed furrow and disrupt seed depth.

Inner scrapers are not adjustable and usually wear in proportion to their disk openers. Problems arise when new disk openers are installed without replacing the inner scrapers. New inner scrapers should be installed any time disk openers are replaced.

  • Impacts with rocks can crack the ends of seed tubes and leave ragged discharge points. Or, if a seed tube isn’t mounted squarely in the row unit, disk openers can wear through one side at the lower end of the tube. Any damage that causes seed to bounce, ricochet or hesitate as it exits the seed tube disrupts seed spacing in the furrow—creating a missing slat or two in the proverbial picket fence.


  • Seed firmers not only wear thinner over time, but lose their elasticity and, hence, their ability to press seeds into place. Seed firmers should have squared or rounded bottom edges. Firmers with V-shaped bottom edges risk pushing seeds to the side of the furrow rather than to the bottom.

Firmers should "snap" firmly into the seed furrow when lifted several inches and then released.
Lethargic spring action causes inconsistent seed depth.

Compare a new seed firmer to an old one to see how much has worn away and how much elasticity has been lost.

  • Each planter manufacturer has its own way of connecting the drill shaft on the center frame to drill shafts on the wing sections of folding planters. No matter what type of coupler is used, make certain both halves of each coupler are aligned when the planter is unfolded and in field position. Then use a wrench to turn the powered side of the connection several complete revolutions. If the coupling doesn’t turn smoothly, re-align or repair the couplers.
  • Drill shaft bearings can drag or catch and cause uneven seed spacing, even though the bearings look fine.
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Plastic seed firmers can wear thin and lose elasticity over time. Replace seed firmers with V-shaped bottom edges and those without sufficient elasticity. Inner disk opener scrapers wear narrower with age, allowing soil to disrupt seed depth in the furrow.

With the planter raised, use a wrench to turn by hand each segment of the drill shaft on a planter.

If one segment turns harder than others, or has noticeable jerks or catches when rotated, remove drive chains or cables from all seed units on that segment to identify if it is from seed units or drill shaft bearings.

If the drill shaft still turns hard with all the seed units disconnected, check for a faulty drill shaft bearing. One by one, unbolt each bearing housing from its mounting bracket and slide it slightly away from its mounting point on the drill shaft. With the bearing free to turn, it’s easy to identify damaged bearings that can add just enough imprecision to prevent a picket fence final stand.

Be sure to visit Dan’s "In The Shop" blog at, where he’ll share more tips and insights. Send comments and story suggestions to

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