Great Plains 3N-4025P Operator Manual - Manual (Page 78)

74 3N-40P Table of Contents Index Great Plains Manufacturing, Inc.
196-538M Table of Contents Index 2014-01-29
Refer to Figure 91
The lift system includes an adjustable stop valve
to fix
the height of the opener frame when the drill is lowered.
Make sure the drill is level and the lift system bled and
re-phased before adjusting the tool bar height.
To adjust the stop height:
1. Move to smooth level ground representative of field
conditions.
2. Lower the drill and measure the present tool bar
height. If the drill cannot be fully lowered due to row
unit spring settings, temporarily move the cams to a
lower setting, or out of notch entirely.
3. Raise the drill.
4. Loosen the knob on the stop .
5. Adjust the stop position on the tube . Adjust up
(to raise) or down (to lower). Adjust by half the last
difference. Secure the stop with the knob bolt
.
6. Lower the drill and measure the tool bar height. If the
error is more than about
1 ⁄
8
inch (3 mm), repeat the
adjustment process from step 3.
7. Raise and lower several times and confirm that the
drill stops consistently at the new height.
Note: It is important that all tires remain in ground contact
to maintain front to rear levelness. Setting the depth
control too deep combined with high opener spring
force can cause the drill to tip forward when
planting, which may cause plugging.
Running with the front tires floating or skimming on
the ground will cause uneven coulter depth and
may cause uneven seed depth.
Figure 91: UMC/NC:
Opener Depth Stop
20274
2
3
1
4
5
1
2 3
3 4
2