TM-9-2320-272-10
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; OPERATOR'S MANUAL
SEPTEMBER 2004
CHANGE 2
TM-9-2320-272-10 - Page 235 of 481
TM 9-2320-272-10
2-134
Change 2
d.
Crane Operation.
The medium wrecker crane is capable of rotating 360°,
extending its boom 18 feet (5.5 meters) and elevating the boom to 45°. A data plate
above crane controls lists variations in safe load crane extension and how it is
rigged. Maximum capacity is 20,000 pounds (9,080 kilograms) with three-part line.
.
WARNING
.
Gondola safety guard must be in place prior to crane operation.
NOTE
• Whenever possible, position wrecker for a direct rear lift.
• This operation requires two crewmembers.
• Vehicle equipped with auto throttle will automatically idle
between 1350 and 1400 rpms.
• Set CTIS to SAND mode after outrigging (M936A2 model
vehicles).
(1)
Park wrecker on a level, hard surface if possible. Wrecker position
depends upon type of lifting operation such as rear lift, side lift, or lift and swing.
(2)
Position outriggers (10) as follows:
(a)
Remove retaining clip (15) holding L-shaped retaining pin (14) at
corner of outrigger frame tube (16) and remove pin (14).
(b)
Pull outrigger (10) out until it stops and lower to a vertical position.
(c)
Insert outrigger handle (12) into hole in collar (9).
(d)
With crewmember holding collar (9), grasp outrigger base (11) and
turn counterclockwise until base (11) makes contact with ground.
(e)
Turn collar (9) clockwise until base (6) seats against ground.
(f)
Repeat procedure to lower remaining outriggers (10).
(3)
Start engine (para. 2-12).
(4)
Place transfer case shift lever (4) in neutral.
(5)
Unlock safety latch (5) and push transfer case power takeoff lever (6)
back to engage.
(6)
Place transmission selector lever (2) in 1-5 (drive).
(7)
Pull out hand throttle control (1) on M936/A1 to last stop.
(8)
If tactical situation permits, turn on amber warning light switch (7), if
required, and floodlight control switch (3) if operation is at night.
(9)
To obtain required lift, adjust shipper braces (17):
(a)
Remove retaining clips (19) securing T-shaped retaining pins (18) to
shipper braces (17).
(b)
Raise boom (8) to required height by pulling boom control lever (13) back.
Adjust height until holes in male and female sections of shipper braces (17) are aligned.
2-24. OPERATION OF MEDIUM WRECKER (Contd)
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