Great Plains 3P4025AH Operator Manual User Manual
Page 57
Great Plains Manufacturing, Inc.
Adjustments
53
2014-07-29
411-099M
An adjuster cam
sets down pressure individually for
each row unit. This is useful for penetrating hard soil and
planting in tire tracks. For best results always adjust
tractor tires so they are not ahead of 30 inch or 70 cm
rows.
Refer to Figure 44
Use only enough down pressure to cut the seed trench
and maintain proper soil-firming over seed. Excessive
row unit down force will lead to premature wear on row
unit components, uneven seed depth and gauge wheel
slippage.
Refer to Figure 43 (shown at cam setting 2),
Figure 44 and Figure 45
To adjust down pressure, use a 1
1
⁄
8
inch (29 mm) open
end wrench or the tool
stored in a bracket at the left
side or the #1 row mount.
1.
Raise the planter. Although this adjustment can be
made with the planter lowered, the springs will be in
tension, and will require more effort. The extra force
required may also damage tools.
2.
Install lift cylinder locks on a 2-point lift-assist model.
3.
Set tractor hitch circuit to Neutral. Put tractor in Park
and shut it off.
4.
Position wrench on the fixed nut
near or slightly
forward of vertical.
5.
Pull upper spring link
back.
6.
Move the adjustment cam
to the new setting on
the spring adjust bar
.
Note: Do not set all rows higher than notch four. Using
high settings across all rows causes uneven
planting. Individual rows may be set higher if
running in tire tracks. On twin-row configurations,
setting all rows to notch 4 or higher results in a net
up force that can exceed the weight of the planter
when the hoppers are nearing empty.
Figure 43
25AP Series Row Unit
Spring Adjustment
31034
3
5
2
2
Cam Notch
Pounds
Kilograms
zero (out of notch)
Lock-Up & Maintenance
one
255
115
two
265
120
three
285
130
four
315
145
five
345
155
six
375
170
tip
Do Not Use
Values are down force with hoppers empty
31947
Figure 44
Row Unit Minimum Cam (at 1)
27065
bottom
4
6
3
Figure 45
Row Unit Maximum Cam (at 6)
27065
top
4
5
2
6