Lull 944E-42 Service Manual - Manual (Page 44)

Boom
3-14 944E-42
26. If needed, pull the second boom section out slightly
to align the extend chain yoke with the bracket.
Route the extend chain yoke and chains around the
sheave on the second boom section. Connect the
yoke to the anchor bracket on the first boom section
with the clevis pin (19). Coat the clevis pin with anti-
seize compound.
27. Check and adjust the boom chains. Refer to Section
3.4.5, “Boom Chain Tension Check.”
28. Properly connect the batteries.
29. Start the engine and operate all boom functions
several times. Check the chain tension again and
adjust as necessary. Check for leaks, and check the
hydraulic fluid level in the tank; add fluid if required.
30. Clean up all debris, hydraulic fluid, etc., in, on, near
and around the machine.
31. Install the rear cover to the boom.
32. Close and secure the engine cover.
3.4 BOOM EXTEND AND RETRACT
CHAINS
3.4.1 Boom Chain Inspection
Under normal operating conditions the boom extend
chains will need to be inspected every
250 hours of
operation. The retract chains need to be exposed and
inspected every 1000 hours of operation. Environmental
conditions and dynamic impulse/shock loads can
drastically affect normal operating conditions and require
more frequent inspection intervals.
Environments in which material handling machines
operate can vary widely from outdoor moisture to
temperature to mildly corrosive or highly corrosive
industrial atmospheres, in addition to abrasive
exposures such as sand and grit. Some effects can be
as follows:
• Moisture - Corrosive rusting reduces chain
strength by pitting and cracking.
• Temperature - Low temperature reduces chain
strength by embrittlement. Going in and out of
cold storage results in moisture from
condensation.
• Chemical Solutions or Vapors - Corrosive attack
on the chain components and/or the mechanical
connections between the chain components.
Cracking can be (and often is) microscopic.
Going from microscopic cracking to complete
failure can be either abrupt or may require an
extended period of time.
MU0211
19
WARNING
Worn pins, stretched or cracked links or corrosive
environments can cause chain failure. A chain failure
could result in uncontrolled boom movement, loss of
load or machine instability.