Great Plains 7336 DH Operator Manual - Manual (Page 29)

Great Plains Manufacturing, Inc. Table of Contents Index Transporting the Disk Harrow 25
2014-06-30 Table of Contents Index 556-235M
Thread Protectors
Refer to Figure 14
10. Make sure thread protector bolts
are in place and
tight. Gang bolt thread damage may occur at hinge
point when gangs flex without protector caps . Lost
caps with no bolt may allow gang nut to become
loose.
Adjusting and Using Tractor Hydraulics
Depth Control
Refer to Figure 15
11. When you have machine level and set to the desired
working depth, set the depth stop on the depth
stop tube . This is located at the front of the
machine. This will maintain a constant depth each
time after raising and lowering machine.One full turn
of the handle
will change the depth approximately
1/4". Turning the crank clockwise 1 turn is a 1/4"
shallower working depth. Turn 2 turns counter
clockwise is 1/2" deeper working depth.
12. Tires must remain on the ground at all times. Wheels
off the ground will induce high loads on level linkage
and hitch, causing premature wear and possible
frame failure.
Tractor Detents
13. After the depth stop on the tractor is set, in order to
preserve the life of the cylinders, it is important to
properly set the detent on the tractor. The 7000
series disk harrow is equipped with re-phasing lift
cylinders. These cylinders have a re-phasing port at
the top of the cylinder (end stroke). If the tractor flow
rates and detents are not set properly, extreme oil
flow through these ports can destroy cylinder seals
causing internal leakage.
14. Tractors with timed detents (electric over hydraulic):
The flow on the tractor should be set so the disk will
raise from field position to full lift in approximately 3
to 5 seconds which is about 10 gpm. Not 10 on the
tractor indicator. More important is the detent. Once
the flow has been set, set the timed detent so that it
is 1/2 to 1 second longer than it takes to fully lift the
unit. If you set it less than this it will not properly
re-phase the cylinders. If you set it more than this,
you may be causing damage to the seals.
Figure 14
Thread Protectors
43415
1
1
2
3
4
Figure 15
Depth Control
43416
2
3
4