Genie GTH-636 Service Manual page 60

Section 3 • Scheduled Maintenance Procedures
CHECKLIST D PROCEDURES
4 Select a reference point on the extension chain.
Measure the distance between the chain and
the top surface of the boom. Note the
measurement (1). Refer to the following
illustrations.
2
5 Move to the fork end of the same boom section
that was just measured.
3 - 30 GTH-636 • GTH-644 • GTH-842 • GTH-844 • GTH-1048 • GTH-1056
6 Measure the distance between the top surface
of the boom and the same reference point used
on the sequencing chain in step 4. Note the
measurement (2).
Result: The difference between measurements
1 and 2 is 0.25 to 0.5 inch / 6.35 to 12.7 mm.
No adjustment to the chain is necessary.
1
Proceed to step 10.
Result: The difference between measurements
1 and 2 is less than a 0.25 inch / 6.35 mm OR
is greater than 0.5 inch / 12.7 mm. The chain
requires adjustment. Proceed to step 7.
Note: The measurements taken in step 4 and step
6 must be taken from the same plane on the boom.
7 Working at the fork end of the boom tube,
locate the adjustable chain anchor on the top of
the boom section.
8 Place an adjustable wrench across the flat part
of the chain, just ahead of the chain anchor.
Tighten the wrench onto the chain.
9 Using a 1
required to tighten or loosen the chain. Repeat
this procedure beginning with step 5.
10 Using a feeler gauge, check the gap between
the coils of the spring. The gap should be no
less than 0.030 inch / 0.76 mm.
Note: The spring coils should never be collapsed
completely.
11 Repeat this procedure, beginning with step 4,
for each extension chain of the boom assembly.
a b c
a nut
b spring
c chain anchor
7 / inch wrench, adjust the nut as
16
June 2007
REV B
Part No. 97487