Lift Chain Adjustment
4000 SRM 764
Lift Chain Adjustment
The following specifications must be correct for cor-
rectly adjusted lift chains (see Figure 13):
• The chain tension must be the same for each chain
of the chain set. Chains that have the same ten-
sion will move the same amount using the same
pressure.
• The chain lengths must be equal for each chain set
and the length must be correct for the mast height.
• The chains must travel freely through the complete
raising and lowering cycle.
1.
Put an 80 to 90 percent capacity load on the forks.
Lower the forks as much as possible.
2.
Check the amount of the bottom operator plat-
form roller extending below the inner mast weld-
ment of the mast. No more than one-third of the
roller can extend below the mast. If the rollers
are too low, adjust the chain anchors. Make sure
each anchor is adjusted the same amount.
NOTE:
When the chain adjustments are complete,
make sure that the threads on the nuts of the chain
anchors are completely engaged. Make sure all of the
adjustment is not removed from the chain anchors so
they cannot move in their sockets.
CAUTION
The minimum thread extending above the nut
of the chain anchor is two times the chain
pitch. Periodic checks must be made to correct
chain adjustments for wear.
3.
Remove the load from the forks. Check the clear-
ance of the operator platform when the mast is
fully extended. The operator platform stops must
not touch the stop at the top of the inner mast
weldment. The chains are too short if the oper-
ator platform touches the stop. Lower the oper-
ator platform completely. Check that the tops of
the forks are the correct height above the floor as
listed below in Step a and Step b. If the forks are
not within the specified height above the floor,
the chains need to be adjusted. If the chains
are too long or too short, adjust the chain an-
chors. Make sure each anchor is adjusted the
same amount.
a. For the standard lift truck, the top of the
forks should be 76.2 ±6.35 mm (3.0 ±0.25 in.)
above the floor in the fully lowered position.
b. For the furniture lift truck, the top of
the forks should be 165.1 ±9.525 mm (6.5
±0.375 in.) above the floor in the fully low-
ered position.
NOTE:
If the chain anchors are too loose, the Lower-
ing Interrupt Switches will prevent lowering of the
platform and mast.
4.
Three-stage mast chain adjustment: Adjust the
main lifting chains until the top of the inner mast
weldment is at the same height as the top of the
outer mast weldment. Adjust the free-lift chain
as described in Step 3.
1.
SECONDARY
WELDMENT
2.
CHAIN SHEAVE
3.
LIFT CHAIN
4.
COTTER PIN
5.
ANCHOR PIN
6.
CHAIN ANCHOR
7.
LOCK NUT
8.
OUTER
WELDMENT
9.
ADJUSTMENT NUT
Figure 13. Lift Chain Adjustments (Main Lift)
18