Great Plains CTA4000 Operator Manual - Manual (Page 43)

Adjustments 39
08/03/2010 160-269M-A
Opener-Subframe Adjustment
At higher down-pressures (above 1200 psi), the row units
can tend to tip forward. An adjustment to the mainframe/
subframe pivot corrects this.
Refer to Figure 45 and Figure 46
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 adjust-
ment bolt
, which occupies one of two positions.
• For low-to-1200 psi down pressures, the adjustment
bolt occupies the middle hole of the frame mount
and trunnion.
• Above 1200, 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 45
Standard Down Force
(below 1200 psi)
26383
1
2
3
4
5
1
2 3
4
5
5
6
Figure 46
High Down Force
(above 1200 psi)
26384
1
6
5
1
6