Great Plains 3N-4025P Operator Manual - Manual (Page 121)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 117
2014-01-29 Table of Contents Index 196-538M
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 4. Using high
settings across all rows causes uneven planting.
Individual rows may be set higher if running in tire
tracks.
Refer to Figure 167
The ideal amount of down-force causes the side gauge
wheels to compress any loose surface soil, but not press
a trench into subsoil.
To assess down-force, operate the drill for a short
distance on typical ground (with or without seeding), and
stop. Leave the drill lowered (row units in ground).
At several row units, inspect the furrow created by the
opener discs, but prior to furrow closing by the press
wheels.
Note: Be sure to inspect rows both in and out of tire
tracks.
Refer to Figure 168
1.
If the side gauge wheels are leaving no tracks, or
light tracks, increase down-force.
2. If the wheels are compressing trash and loose soil,
and leaving clear tracks right at the top of the
subsoil, down-force is probably correct and needs no
adjustment.
3. If the wheels are creating a trench into the subsoil,
down-force is too high and needs to be reduced.
Figure 166
Row Unit Maximum Cam (6)
27065
5
2
6
Figure 167: 25 Series:
Checking Furrow
25193
{
Inspect Furrow Here
Light or no side gauge
wheel tracks Insufficient down-force
Increase down-force
Gauge wheels compress
loose soil only Ideal
No adjustment required
Side gauge wheels
making deep tracks Down-force too high
Reduce down-force
Figure 168: 25 Series:
Assessing Down-force
1
2
3