
31200243 109
Maintenance Section
Illustration 180 g01109371
Illustration 181 g01109372
4. Set the minimum distance to 224 mm (8.8 inch)
between boom section 2 and boom section 3. The
maximum allowable distance is 234 mm (9.2 inch).
Tighten extension chain (1) in order to move
section 3 outward. Tighten retraction chain (2) in
order to move section 3 inward. If the distance is
significantly more than 224 mm (8.8 inch), slacken
both chains and refer to Step 1.
5. After setting the distance to the required tolerance,
tighten the extension chain to 20 N-m (15 lb ft).
6. Tighten the retraction chain to 18 N-m (13 lb ft).
7. Tighten the extension chain to 105 ± 5 Nm
(77 ± 4 lb ft).
8. Tighten the retraction chain to 70 ± 5 Nm (52 ± 4
lb ft).
9. Extend the boom and retract the boom several
times. Check the torque for the extension chain.
Check the torque for the retraction chain.
10. Install the locknut for the extension chain. Torque the
locknut for the extension chain to 105 ± 5 Nm (77 ±
4 lb ft).
11. Install the locknut for the retraction chain. Torque the
locknut for the retraction chain to 70 ± 5 Nm (52 ±
4 lb ft).
12. Check the shackles on both chains. If necessary,
adjust the shackles in order to set the shackles
horizontally.
13. Remove the stand and lower the boom.
Measure the Chain for Wear
Nominal pitch of the link equals 25.4 mm (1 inch).
Nominal height of the plate equals 24.1 mm (0.95
inch).
1. Fully retract the boom. Position the boom
horizontally.
2. Extend the boom by 2 m (6 ft 7 inch) or extend the
boom to the section of chain that most frequently
passes over the boom extension chain pulley.
Do not retract the boom sections before you begin
to measure the chains.
Illustration 182 g00747739
3. Use a caliper in order to measure the height of
inner plate (A) and the height of outer plate (A)
over 15 pitches of the selected worn section of
chain. If any inner plate or any outer plate shows a
reduction in height of more than 5% wear, all chains
must be replaced. Also, if the measurement is less
than 22.89 mm (0.901 inch), all chains must be
replaced.
4. Use a 6V- 0028 Wear Gauge As (CHAIN) in order to
measure the chain between the 16 pin centers of
the selected worn section (B). The nominal length
of 16 pin centers is 381 mm (15 inch).If the
measurement shows an elongation of more that
2%, all chains must be replaced. Also, if the
measurement is greater than 388.6 mm (15.30
inch), all chains must be replaced.