Great Plains 3N-4025P Operator Manual - Manual (Page 43)

4/23/2010 196-286M
41 Adjustments
25 Series Openers
Seeding depth is controlled by gauge wheels
mounted on the sides of the opener disks.
Do not back up with openers in the ground. To do so
will cause severe damage and opener plugging.
Opener Down Pressure
Refer to Figure 44
Opener springs provide the down pressure nec-
essary for opener disks to open a seed trench.
The springs allow the openers to float down into
depressions and up over obstructions.
You can adjust down pressure individually for
each opener. This is useful for penetrating hard
soil and planting in tire tracks. For best results al-
ways adjust tractor tires so they are not ahead of
30” rows.
Use only enough down pressure to cut the seed
trench and maintain proper soil-firming over seed.
Excessive opener down force will lead to prema-
ture wear opener components. Excessive down
force will also cause uneven seed depth.
Refer to Figure 45
To adjust down pressure, use a 1 1/8” open end
wrench. Position wrench on the nut and pull down.
Move the adjustment cam to the new setting.
Figure 44
25 Series Opener Springs
Opener spring
21947
Figure 45
Opener Down Pressure Adjustment
21948