Doosan D20S-5 Operation & Maintenance Manual page 228

Maintenance Section
Carriage Chain Adjustment
Make sure that carriage height is correct. If correct,
adjust the chain for equal tension. If not, adjust the
chain for correct carriage height by adjusting
anchor nuts (1), (2).
NOTE: See the previous section, "Carriage Roller
Extrusion" in "When Required" for proper
height of carriage.
1. Fully lower the carriage and tilt mast forward or
lift the carriage and put blocks under the carriage
to release the tension from the lift chains.
2. Loosen nut(1) and adjust nut(2) to get proper
distance from bottom of inner upright to the
bottom of carriage bearing.
Typical example for carriage chain of STD mast
Typical example for carriage chain of FF, FFT mast
3. Make adjustment anchor nut (1), (2) for equal
chain tension.
4. Set the mast vertical and raise the carriage and
check equal chain tension. If not equal, repeat
the same procedure as step 1 through step 3.
5. Put LOCTITE No. 242 Tread lock on the threads
of the anchor nuts (1), (2) after the adjustment is
completed.
Mast Chain Adjustment - FF, FFT Mast
Typical example for FF mast
Typical example for FFT mast
Make sure that mast height is correct. If correct,
adjust chain for equal tension. If not, adjust mast
chain for correct mast height by adjusting anchor
nuts (3), (4).
NOTE: See the previous section, "Carriage Roller
Extrusion" in "When Required" for proper
inner mast height.
1. Lift the inner mast and put blocks under the inner
mast to release the tension from the lift chains.
2. Loosen nut (3) and adjust nut (4) to make inner
mast rail flush with outer mast rail bottom.
3. Make adjustment anchor nuts (3), (4) for equal
chain tension.
4. Raise the inner mast and check equal chain
tension. If not equal, repeat the same procedure
as step 1 through step 3.
5. Put LOCTITE No. 242 tread lock on the threads
of the anchor nuts (3), (4) after the adjustment is
completed.
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