Great Plains CTA4000 HD Operator Manual - Manual (Page 49)

Great Plains Manufacturing, Inc. Adjustments 45
2012-11-28 160-037M
Opener-Subframe Adjustment
At higher down-pressures (above 1600 psi), the row
units can tend to tip forward. An adjust to the
mainframe/subframe pivot corrects this.
Refer to Figure 58 and Figure 59
The opener tool bar
is supported entirely by eight
arms at the lift cylinders (not shown). The trunnion
at the arm end is connected to the tool bar by a lower
pivot bolt
which is never moved.
The arm-tool bar angle is controlled by an upper
adjustment bolt
, which occupies one of two positions.
• For low-to-1600 psi down pressures, the adjustment
bolt occupies the middle hole of the frame mount
and trunnion.
• Above 1600, the adjustment bolt occupies the top
hole of the frame mount and trunnion.
Set all arms the same.
To change the bolts (to high pressure):
1. Have a jack at hand.
2. Loosen the nuts on all the top bolts .
3. Lower the opener sub-frames.
4. Leave the valve handles set to FIELD.
5. Put the tractor hydraulic circuit in float.
6. Place jack under an opener tool bar at an arm .
7. Lift the tool bar until the bolt is free.
8. Remove the bolt.
9. Repeat step 6 through step 8 the other arm of the
subframe.
10. Raise the jack until the top holes are aligned.
11. Insert the bolt in the top hole and spin on a nut.
12. Repeat step 6 through step 11 for each sub-frame.
13. Tighten all nuts.
Changing from high to low is similar, except lower the
jack at step 7 and reverse the bolt movement.
Figure 58
Standard Down Force
(below 1600 psi)
26383
1
2
3
4
5
1
2 3
4
5
5
6
Figure 59
High Down Force
(above 1600 psi)
26384
1
6
5
1
6