TM 9-2350-256-34-2
CHAPTER 3
REPAIR INSTRUCTIONS
Section I. REPAIR OF HOISTING BOOM ASSEMBLY
3-1 Description
The hoisting boom (fig. 1-13) is a tubular A-frame, and is pivot-mounted to the top front of the vehicle. Hydraulic
pressure raises or lowers the boom by means of two boom-actuating cylinders which are activated by the boom control
lever. The hoisting boom is capable of holding a 25-ton load. In operating position, the boom is supported by a stayline
cable secured to crank arms located at the rear of the hull. These crank arms are connected to hydraulically actuated
stayline cylinders which govern the reaching capacity of the hoisting boom. A boom travel lock is provided for preventing
movement of the boom, particularly sideways, while traveling.
3-2 Disassembly of Hoisting Boom Assembly into Subassemblies
CAUTION
LOAD TEST REQUIREMENT
a. Load testing of main winch, hoist winch and boom is mandatory, prior
to use under any of the following conditions:
(1) When new.
(2) Following any repairs, disassembly and assembly, adjustments
or parts replacement of hoist winch or boom.
(3) When modifications are made that could affect the strength or
lifting capabilities of the vehicle.
b. Load testing will be accomplished by support maintenance activities.
c. Refer to Chapter 2, Section V for detailed step-by-step procedures.
a. General. Figure3-1 shows the subassemblies and attaching parts of the hoisting boom assembly.
b. Disassembly Procedure. The peculiar nature of the hoisting boom assembly makes it necessary to disassemble it
into subassemblies during removal. For detailed instructions concerning removal and disassembly into subassemblies,
refer to TM 9-2350-256-34-1.
Change 4
3-1
