TM-9-2320-272-24-3

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 3 OF 4

JUNE 1998

TM-9-2320-272-24-3 - Page 650 of 799

4-194. BOOM

TM 2320-272-24-3

1.

2.

3.

4.

5.

6.

7.

Install utility chain to secure inner boom (1) to outer boom (2).

Attach two utility chains on outer boom (2).

Hoist outer boom (2) over wrecker and position on turntable (8).

Assemble two sleeve bearings (9) and sheave (10), align sheave (10) with holes in turntable (8) and

outer boom (2), and install boom (2) on turntable (8) with pivot pin (7) and new locknut (11). Tighten

locknut (11) 800-1,000 lb-ft(1,185-1,356 N•m).

Install grease fittings (6) and (12) on pivot pin (7).

Connect two elevating cylinders (13) to boom (2) with two retaining pins (16), new lockwashers (15),

and screws (14). Tighten screws (14) 44-61 lb-ft (60-83 N•m).

Using lifting device and utility chains, lift outer boom (2) and disconnect shipper braces from

boom (2) (TM 9-2320-272-10).

8.

Connect cylinder extension hose (5) and retracting hose (4) to two boom adapter elbows (3).

9.

Remove utility chains from outer boom (2).

Before hoisting outer boom to wrecker, ensure that inner boom is

secured to outer boom as outlined in steps of removal procedure.

NOTE

If installing new boom assembly, use hardware from old boom.

4-914