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 241 of 481

TM 9-2320-272-10

2-24. OPERATION OF MEDIUM WRECKER (Contd)

2-140

(n)

Install boom jack (1) in base plate (3) and secure in place with

retaining pin (7) and retaining clip (8).

(o)

Obtain tie bar (2) from wrecker bed and install between boom

jacks (1). Secure in place with retaining pin (5) and retaining clip (6).

(p)

Push boom control lever (9) to DOWN position, and release it when

boom jacks (1) make firm contact with ground.

(q)

Perform lifting and lowering operation. Refer to steps 10 and 11.

(14)

Heavy side lifts are similar to heavy rear lifts except that front and rear

outriggers (4) from the lifting side of the vehicle will be positioned.

e.

Towing With Wrecker Crane.

.

WARNING

.

• If vehicle being towed has inoperative compressed air system,

emergency air and service air lines must not be connected

between vehicles. Failure to do this may result in damage to

equipment, or cause injury or death.

• If the compressed air system of the vehicle being towed has

emergency air and service air lines, they must not be connected.

CAUTION

• Do not use towing as a means to start engine of vehicle with

automatic transmission. Refer to disabled vehicle operator’s

manual for towing instruction. Failure to so may will result

in damage to vehicle.

• Maximum towing speed shall not exceed 35 mph (56 km/h) on

paved highway or 15 mph (24 km/h) on off-highway surfaces.

NOTE

When towing M939/A1/A2 series vehicles with inoperative

compressed air system, the spring brakes must be caged.