Mack M123 tractor truck and M125 truck

M 123
Mack M123 semi-tractor
Type	10 ton (9,072kg) 6x6 Semi-tractor
Place of origin	United States
Production history
Manufacturer	Mack, CONDEC
Produced	1955-1969 (M123) 1957-1958 (M125),
Number built	392 (Mack), 3188 (CONDEC) 552 (M125)
Variants	M 125 Prime Mover
Specifications (M123^[1])
Weight	32,490 lb (14,740 kg) empty
Length	280 in (7.11 m)
Width	114 in (2.90 m)
Height	111 in (2.82 m)

Engine	Le Roi TH-844 297 hp (221 kW)
Transmission	5 speed x 2 range trf. case
Suspension	Beam axles on leaf springs
Fuel capacity	83 US gal (310 l)
Operational range	300 mi (482.8 km)
Speed	42 mph (68 km/h)

The Mack M123 was a 10-Ton (9,072 kg) 6x6 gasoline-powered prime mover introduced in 1955; the Mack M125 was a 10-Ton heavy cargo truck version of the M123.

Each was subsequently upgraded with a diesel engine, as M123A and M125A, respectively. Both these saw service in the Vietnam War.^[2] (2)

M123

Variants:

M123 had dual winches and high mounted fifth wheel, gasoline engine

M123A1 had a single rear winch and a V-8 diesel engine (300 hp (224 kW)).

M123C had a single midship winch and low mounted fifth wheel, gasoline engine

M123D had dual midship winches and low mounted fifth wheel, gasoline engine

M123AC1, built from 1965 to 1969 by CONDEC, had a diesel engine and single rear winch

M123E1 were M123's that were re-engined with the diesel engine.

M123E2 with dual rear winches, diesel engine

In addition to the US Army, the M123 was used by the U.S. Marine Corps and exported to U.S. allies in such countries as Australia and Spain.

The last manufacturer of the M123 was the Consolidated Diesel Electric Corporation.

It was used to tow semi-trailers carrying MBT's (in conjunction with the M15A1 and later the M747 semi-trailer) and as such superseded the M26(A1) Pacific "Dragon Wagon") and semi-trailers carrying engineering equipment (e.g. in conjunction with the M 127 low bed semi-trailer).

Technical information

Engine: LeRoi T-H844 V8-cyl. 844 cu in (13.8 L) ohv gasoline engine, 297 hp (221 kW) at 2600 rpm Later: Cummins V8-300 diesel rated at 300 hp (224 kW) horsepower at 3000 rpm.

Gearbox: Mack TRDXT72 5F1R

Tires: 14.00 x 24 inch.

M125

The M123-derived M125 succeeded the Mack NO as a heavy cargo transport vehicle; it also served as a prime mover towing the 155-mm gun and 8-in. howitzer. The chassis was designated M121. It had a 14-ft14 ft (4.27 m) steel cargo body with folding troop seats, bows and canvas cover.^[2] A single front-mounted Gar Wood DSA716 45,000 lb (20,000 kg) capacity winch was fitted, and a chain hoist at rear for handling ammunition.

About 550 units were built.

Variant

M125A1 was fitted with the same Cummins diesel engine as the M123A.

Gallery

MACK-123-AND-125
M123 AND m125.2 (3)
M123 AND m125.1 (3)
M123 AND m125.2 2)

References

↑ "TM-9-2320-206-10 Operator’s manual for Truck tractor 10 ton, 6X6, M123, Cargo M125". US Dept. Of the Army. April 1977. Retrieved 31 December 2014.
↑ 2.0 2.1 Vanderveen, Bart (1998). A record of military Macks in the Services and Beyond. Battle of Britain International Ltd. pp. 114–116. ISBN 1 870067 09 6.

ORD 7 SNL G-792 (31 January 1958) Section I, LeRoi engine parts.
TM 9-8002 (1 November 1955)
TM 9-8003-1 (25 June 1956) Ordnance Maintenance for Engine, Engine Accessories and Clutch
TM 9-2815-213-34 "Cummins V8-300 Maintenance". US Dept. of the Army. 2 Feb 1972. Retrieved 15 Dec 2014.
TM 9-2320-206-10 (29 April 1977) Operator's Manual
TM 9-2320-206-10HR (8 December 1978) HR Hand Receipt
TM 9-2320-206-12 (4 February 1960) Supersedes TM 9-8002 & ORD 7 SNL G792
TM 9-2320-206-20 (22 October 1971) Organizational Maintenance
TM 9-2320-206-20P Parts
TM 9-2320-206-34 Direct & General Support Maintenance
TM 9-2320-206-34P (6 March 1972) Direct & General Support Maintenance Repair Parts & Special Tools List
TM 9-2320-206-ESC (ESC stands for Equipment Serviceability Criteria)
LO 9-2320-206-12 Lube Order

Notes