Chain maintenance, Chain slack, Gearbox maintenance – Great Plains 606NT Operator Manual User Manual
Page 51

Great Plains Manufacturing, Inc.
Maintenance and Lubrication
47
2014-02-10
151-061M
Chain Maintenance
Initially check the drive chains after the first 10 hours of
drill use. The slack of new chains tends to increase
during the first few hours of operation due to seating.
Thereafter, check the chains every 100 hours.
Lubricate chains any time there is a chance of moisture,
and when being stored at the end of the planting season.
Chain Slack
Refer to Figure 48, which, for clarity, greatly exaggerates
slack, and omits the idlers.
1.
Measure the span
for allowable slack:
Locate the longest span of each chain (usually the
span which does not run through the idlers).
2.
Determine the ideal slack:
Long chains (over 36 inches / 91 cm):
1
⁄
4
in. per ft (21 mm/m)
Vertical short chains:
1
⁄
4
in. per ft (21 mm/m)
Horizontal short chains:
1
⁄
2
in. per foot (42 mm/m).
3.
Measure the current slack
:
Acting at a right angle to the chain span at the centre
of the span, deflect the chain in both directions. The
slack is the distance of the movement.
4.
Adjust the idlers for ideal slack.
Whenever mounting a chain, make sure the clip at the
removable link is oriented to minimize snags.
Refer to Figure 49 (arrow shows chain direction)
Install clip with open end facing away from direction of
chain travel (shown by gray or striped arrows in chain
routing diagrams).
Gearbox Maintenance
The gearbox is lubricated and sealed at the factory.
Under normal conditions, it does not require
maintenance or lubrication.
If the gearbox has been opened for repair, repack all
gears and around shaft bearings using at least
7 oz. (200 mL) of gear lube, Great Plains Part No.
788067.
Keep moisture and dirt out of gearbox. Inspect (replace if
needed) the rubber seals on gearbox drive and shifter
shafts.
Spread a small skim coat of anaerobic sealant
(Loctite
®a
525 or equivalent) to gear case mating
surfaces before bolting them back together.
Figure 48
Measuring Chain Slack
27264
2
1
1
Figure 49
Chain Clip Orientation
26482
2
14757
Machine Damage Risk:
Use sealant sparingly. Excess sealant may squeeze off the
intended surface and lock bearings or gears.