Great Plains YP4025A Operator Manual - Manual (Page 118)

114 YP4025A Table of Contents Index Great Plains Manufacturing, Inc.
401-627M Table of Contents Index 2013-04-24
Chain Maintenance
Inspect and lubricate chains regularly. The slack of new
chains tends to increase during the first few hours of
operation due to seating.
See also “Chain Routing” on page 154.
Chain Slack
Check slack at fixed idlers within the first 8 hours of
operation and tighten idlers as necessary. Check slack at
spring-operated idlers seasonally.
Refer to Figure 141, 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 36in/91cm):
1 ⁄
4
in per foot
Vertical short chains:
1 ⁄
4
in per foot (2.1cm/m)
Horizontal short chains:
1 ⁄
2
in per foot (4.2cm/m).
3. Measure the current slack :
Acting at a right angle to the chain span at the center
of the span, deflect the chain in both directions. The
slack is the distance of the movement.
4. Adjust the idlers for ideal slack.
Chain Clips
Whenever mounting a chain, make sure the clip at the
removable link is oriented to minimize snags.
Refer to Figure 142 (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).
Meter Drive Chain
Refer to Figure 143 (which depicts planter raised)
When performing periodic lubrication, check chain
condition. Replace chain if any frozen kinks are not
corrected by lubrication.
When performing seasonal checks, lower planter to put
chain at minimum idler spring tension.
Check that idler spring length , measured from outside
of pin to outside of pin, is not shorter than:
7.0in (17.8 cm)
Lift spring off idler assembly . Check that idler
assembly pivots freely. Re-attach spring.
Check chain clip orientation. Check chain routing at
shank idler(s)
(see page 157).
Figure 141
Measuring Chain Slack
27264
2
1
1
Figure 142
Chain Clip Orientation
26482
2
Figure 143
25AP Meter Drive Chain
29616
5
4
3
3
4
5