In The Shop: High-Mileage Planter Repair

February 11, 2017 02:03 AM
In The Shop: High-Mileage Planter Repair

Most farmers are aware of common wear and maintenance points on planters. Worn disk openers, failed closing wheel bearings and other high-wear components are annual gotta-check issues prior to planting.

But as planters pass their 10th birthday, wear on other components becomes an issue. Here are a few less obvious wear points and maintenance concerns that develop on planters with a little age:

  • The metal impellers inside vacuum fan housings move tremendous volumes of air, thick with fine, powdery field dust. Over time the vanes on those impellers get sand-blasted so thin they break, throwing the high-speed fans out of balance. Even subtle imbalances create vibrations that damage seals and cause leaks on hydraulic motors that power vacuum fans. 

Preseason, remove bolts and split fan housings. Check for excessive impeller wear to sidestep motor failures and in-field repairs.

  • Abrasive wear can also cause the seed holes in vacuum seed disks to become out-of-round. Use an appropriate-size drill bit as a go/no-go gauge to identify seed holes worn to an oval shape and avoid uneven singulation due to erratic seed retention against seed plates.
  • Rubber seals on the doors of vacuum meters that press against seed plates when the doors are closed wear a groove in the seed plates. Replace any seed disk with a groove around the edge more than 3⁄16" deep.
  • Farmers who replace worn seed furrow disk openers sometimes overlook the metal divider/scraper mounted between the openers. Sometimes called a “frog,” this scraper fits loosely between the disks but provides essential dirt and mud-scraping action to create a crisp, V-shaped seed furrow. 
  • Drill shaft bearings on planters die silent deaths that often go unnoticed. They don’t fly apart and advertise their failure like bearings on combines and balers. 

“Stiff” drill shaft bearings jerk as they turn and contribute to uneven seed metering. Frozen bearings simply lock up and stop seed meters.

To identify problematic drill shaft bearings, first uncouple drive chains from seed transmissions or hydraulic drive motors to allow free movement of drill shafts. Next, use a wrench to turn by hand each segment of drill shaft on a planter’s wings and main frame. 

Excessive drag or jerky motion from a particular shaft merits removing individual seed meter drive chains or drive-shafts to identify the specific bearing causing the problem.

  • Finger-type seed meters obviously have multiple small moving parts that develop wear over time.  

The singulating “bump” just ahead of the exit hole on finger unit backing plates is notorious for wearing out over time. Less obvious is wear to the base of fingers, where they ride on the cam under the center plastic cover. 

Running finger units on a seed meter test stand is the best way to identify variations in metering accuracy related to subtle wear between the various components.

  • On vacuum seed meters, the small knock-out wheels mounted in vacuum meter doors eventually wear and get wobbly on their axle. Vacuum meters that use spring-loaded double-eliminators and small pointed cones to clean debris from seed plate holes need to have those wear points checked annually.
  • Seed firmers, those plastic wands that trail in the seed furrow to press seeds into the soil, wear out in two ways. They literally wear thinner as their plastic lower surface and sides erode due to contact with the soil.

They also lose the elasticity in their stem that allows them to consistently press the seeds into the bottom of the furrow. 

Seed firmer manufacturers don’t offer wear specifications, but they generally recommend replacing seed firmer wands every three to four years to ensure proper thickness and elasticity.

  • A little wear, a little corrosion, to each of the roller chains on a planter can add up to enough friction to create metering inaccuracy and head-scratching problems because there’s no single, obvious component causing the problem.

Remove a couple seed meter drive chains and pull them over your finger or the handle of a wrench. Any chain that doesn’t flow smoothly adds a jerk or hesitation every time it goes around a sprocket. Multiply those jerks, hesitations and increased torque by the number of chains on the planter and minor problems become major issues that are tough to diagnose. Be sure to check all chains on seed drive transmissions as well as any ground drive chains. 

Worn sprockets can contribute to chain-related problems. Be wary of any sprocket with hooked teeth that can feed jerks and hesitations into seed meter drive systems.

  • Row cleaners wear in a variety of ways. Wear to fluted coulters not only reduces their diameter but dulls their residue-cutting edge.

Tined row cleaners wear both shorter and thinner. Shorter tines have less clearance between their tips and hub, increasing problems with root balls and small rocks. Thinner tines bend more easily, leading to issues where two tines don’t intermesh correctly, clog and drag dirt.

  • Seed monitor problems on high-acreage planters can often be traced to seed tube sensors. The clear plastic covers over the sensors in a seed tube get scratched and glazed after tens of thousands of seeds slide over their surface. Symptoms of impaired sensor covers are single rows that show low population on the monitor but prove to be planting accurately in the seed furrow behind the planter. Replace the seed tube sensor to correct the problem.
  • Wiring harnesses can also wear with long use. Quite simply, the plastic zip ties or electrical tape used to keep seed monitor wires away from moving parts and pinch points get brittle with age. The fasteners break and seed monitor wires get caught or pinched, especially in the parallel arms between the planter main frame and seed tube sensors. 

Individual rows that are actually planting accurately but show complete failure on the seed monitor suggest problems with the seed sensor wiring to that specific row. A pre-season check for broken zip ties or errant wires and wiring harnesses can avoid problems in the field. 



Back to news


Spell Check

No comments have been posted to this News Article

Corn College TV Education Series


Get nearly 8 hours of educational video with Farm Journal's top agronomists. Produced in the field and neatly organized by topic, from spring prep to post-harvest. Order now!


Market Data provided by
Brought to you by Beyer