Installation Instructional Video for John Deer 40/90 Series Corn Heads
- 00:00 – Intro
- 00:36 – Tools Needed
- 02:23 – Removing Hoods, Gathering Chains and Sprockets
- 09:44 – Removing Grass Knives
- 11:15 – Removing Stalk Rolls
- 16:42 – Removing Stuck Stalk Rolls
- 18:11 – Checking Pinion Shafts and Seals
- 19:27 – Check Pinion Shaft Timing
- 18:52 – Installing BT Chopper Stalk Rolls
- 29:26 – Installing Calmer Grass Knives
- 32:30: Installing Anti-Hairball Insert
- 34:17 – Installing Calmer Stripper Plates
- 35:15 – Setting Stripper Plate Gap
- 42:07 – Installing Idler Sprockets
- 46:42 – Installing Drive Sprockets
- 47:33 – Installing Idler Blocks
- 48:30 – Installing Gathering Chains
Row Unit Replacement Tool List:
- 1 1/8th or 1/14 wrench
- 15/16th wrenches
- 18mm wrench
- 15/16th socket
- 18mm socket
- 3/4 inch socket
- air hammer 1/2 inch punch
- impact driver
- 1/2″ ratchet, 3/8″ ratchet for socets
- dead blow hammer (soft blow mallet)
- steel hammer
- snap wring pliers
- hex bit (included in mailing)
- torque wrench 85+ fp
- putty knife or scraper
- marker, or paint pen
- cut resistant gloves
40-90 Series Oil Bath Setup and Maintenance Tips:
For 40 Series and Older 90 Series Corn Heads Only: Using a 64-tooth sprocket (JD Part # AH145940) on the cross auger instead of the factory 54-tooth will slow the auger down and help reduce ear toss. This 64-tooth sprocket uses a #50 roller chain. The new 90 series corn head cross augers come from the factory already slowed down with a 52-tooth sprocket that uses a #60 roller chain.
Oil Bath Settings
The corn head should have the oil bath in overdrive, the large sprocket on the back (driver), and the small sprocket on the front (driven).
40/90 Corn Head Gear Ratios
• 693: 30 Driver; 25 Driven
• 893: 30 Driver; 25 Driven
• 1293: 22 Driver; 18 Driven
• 1290: 22 Driver; 18 Driven
Feeder House Settings for JD Combines
Standing Corn: 600-610 RPM on variable speed. As previously mentioned, we suggest staying
on fast setting (large sprocket) for the feeder chain speed when harvesting.
• Must have heavy duty reverser (8 rows or above have a finned aluminum cooler (recommended
by John Deere).
• Only use fully synthetic oil in the reverser.
• There are 2 grease fittings on the reverser. These need to be placed at the 12 o’clock and 2
o’clock positions. Put 12 pumps of grease in the fitting located at 12 o’clock and 2 pumps of
grease in the fitting located at 2 o’clock. Do Not Over Grease!
• Once you start-up the machine, at idle, run the variable speed up and down twice to lubricate
properly prior to harvest.
Down Corn: 500-550 RPM on variable speed.
JD Corn Head on Case Combine or
non-variable speed Feeder House
• JD 693: 34 Driver; 22 Driven
• JD 893: 34 Driver; 22 Driven