This time of year, customers routinely come in with questions about maintaining or repairing their planters. Such as:
-When should I replace disk openers? We recommend replacing disk openers that measure 15 inches in diameter when new are worn to 14-1/2." Some manufacturers allow more wear than that before replacement, but our experience is that disks wear "thinner" as they decrease in diameter. Below 14-1/2" the disks become thin enough so the edges roll or crimp when they hit rocks, which causes problems.
-What else needs to be replaced when I replace disk openers? Always replace the "frog," the cast iron inside scraper that fits between the front of the disk openers. That frog doesn't look important, but if you compare a new one to an old one, you'll see a difference in width that proves they are a wear item that needs regular replacement.
-Why can't I get my gauge wheel tires to consistently "squeegee" the disk openers? Long story short, either the gauge wheel arm, or the stub on which the gauge wheel arm pivots, is worn. Talk to your local dealership--there are a lot of aftermarket and OEM options on replacing or rebuilding those pivots and arms.
-Can I replace the bearing in gauge wheel tires/Can I install new gauge wheel tires on my gauge wheel "split rims"? Yes, you can, but it will take your more than an hour per wheel to unbolt and split the rim, replace the bearing, and install a new tire. And when you're finished there's a very good chance the tire/wheel/bearing will be cocked enough so the assembly doesn't spin true if you hold the gauge wheel arm in the air and spin the gauge wheel tire. Personally, I replace the entire gauge wheel tire, bearing and split rim as factory-assembled unit. It takes 15 minutes, and I've got a new tire and bearing on a wheel that runs true when I spin it.
-What other wear-points should I check on my planter? Check to make sure the disk scrapers are in place and not worn out. Check all closing wheel bearings, and that the outside edges of closing wheel rims aren't worn thin. Check that the spring which provides tension on the closing wheel frames (that's the coil spring inside the closing wheel frame) hasn't worn through the cast iron loop where the front of the spring attaches. Check for broken down-pressure springs on the front of the row unit, and check the seed disks inside the seed meters to make sure they haven't got a deep groove worn where the rubber door seal runs against that disk. Check that singulators and double-eliminators inside vacuum seed meters are at factory specs--which means near-new.
A final note about seed meters. After running thousands of finger-type seed meters on test stands, our dealership has determined that they can be exceptionally accurate, but are extremely finicky. Worn units will plant consistently, but not perfectly. All parts must be near new and well-tuned for optimum performance, and the ONLY way to meet that ideal is to have each unit tuned on a test stand. You can get a stand of corn you're proud of with a worn finger unit, but you'll get a stand of corn you'll brag about with tuned units. The same goes for vacuum units-- you can get a good stand with just about any vacuum unit that isn't broken in some way, but the best stands come from vacuum units that have been individually tuned. What I'm saying is that any planter in average condition will plant corn. But if you want perfect spacing and consistent depth, every aspect of the planter, from the disk openers to the seed meters to the closing wheels, has to be in just-left-the-factory condition.