Adjusting Gearbox Drive Chain Tension - MacDon FlexDraper FD1 Series Operator's Manual

5.6.5 Adjusting Gearbox Drive Chain Tension

The gearbox drive chain tension is factory-set, but tension adjustments are required after the first 50 hours, then
every 500 hours or annually (whichever comes first). The gearbox drive chain, located inside the gearbox, requires
no other regular maintenance.
DANGER
To avoid bodily injury or death from unexpected start-up of machine, always stop engine and remove key
from ignition before leaving operator's seat for any reason.
1. Lower the header.
2. Shut down the combine, and remove the key from the
ignition.
3. Remove two bolts and the chain adjusting cover (A).
Ensure there is no gasket (B) damage.
4. Remove the retainer plate (C).
5. Tighten bolt (D) to 6.8 Nm (60 lbf∙in).
6. Refer to Table 5.1, page 418
bolt (D) based on your gearbox configuration.
NOTE:
A properly tensioned chain has 10–14 mm (3/8–
9/16 in.) of deflection at its midpoint.
7. Reinstall the retainer plate (C).
8. Reinstall the chain adjusting cover (A) and gasket (B).
Torque hardware to 9.5 Nm (84 lbf∙in).
Table 5.1 Adjusting Bolt Tightness on Configured Gearboxes
Gearbox Configuration
CLAAS
Case, New Holland,
and AGCO (Challenger, Gleaner,
Massey Ferguson)
John Deere
214683
MAINTENANCE AND SERVICING
and back off (loosen)
Gear Ratios
22/38 sprocket ratio, 74 pitch chain
29/38 sprocket ratio, 78 pitch chain
37/38 sprocket ratio, 80 pitch chain
418
Figure 5.47: Chain Tensioner
A
B
C
D
Back Off Amounts
1 turn
1 turn
2-1/2 turn
Revision A