TM-9-2350-256-34
RECOVERY VEHICLE, FULL TRACKED: MEDIUM, M88A1
TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL
JULY 2005
TM-9-2350-256-34 - Page 24 of 584
TM 9-2350-256-34
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Main Engine Generator System–Continued
the vehicle batteries. Control of the electrical system is maintained by the driver through a series of instruments and switches
mounted on control panels in the driver’s area. A system of electrical harnesses interconnects the various components of the
vehicle electrical system. Waterproof connections are provided for harnesses and components.
Auxiliary Generating System
The auxiliary generating system consists of a dc voltage generator driven by a diesel engine. A solid-state voltage regulator
serves to maintain a constant generator output voltage of 28 ± 0.7 volts dc when the generator is powering the system and
charging the batteries. This voltage regulator has an internal current limiting circuit which the APU generator interpole (APU
regulator plug pin E) voltage to 0.48 ± 0.03 volt dc. This corresponds to a nominally regulated generator output of 160 amps dc,
with a maximum generator output of 180 amps dc.
New Dual Voltage Regulator System
The main and auxiliary engine can be operated together or individually as desired to recharge the vehicle batteries. With the
new dual voltage regulator system, during the periods of cold weather starting, the auxiliary engine can now be started and left
running to aid the vehicle battery charge condition, while attempting to start the main engine.
Harnesses
The cables and wires carrying the electrical circuits, serving the various components of the electrical system, are assembled
into harnesses. These carry the interconnecting splices in protective covering and incorporate various types of terminals. These
terminals make positive and secure electrical connections at the various points served by the harness and provide for easy
connection and disconnection without splicing or soldering.
Transmission and Output Reduction Units
The Allison Model XT-1410-4 cross-drive transmission is a combined transmission and steering unit. It consists of a basic
transmission unit package to which has been added the torque-converter package (front), steering-clutch packages (both sides)
and the output-reduction-gear packages (both sides). The output-reduction-gear packages contain the brakes, and together with
the sprocket hubs, make up the output reduction units. The outer flange of each output-reduction-gear output shaft assembly
carries 10 studs for attaching the sprocket hub. The transmission provides a fluid torque converter connection between engine
and final drive and three selective gear ratios forward and one ration in reverse. Repair information is contained in TM 9-2520-
215-34.
Tracks and Suspension
The track laying system includes 12 dual road wheels (six on each side) that ride on the two 84-link tracks. Two double sprocket
hubs power the tracks. Two compensating idler dual wheels and six track support dual rollers (three on each side) make up the
balance of the track laying portion of the track and suspension system. The road wheels are mounted on suspension arms which
bear the weight of the vehicle. Torsion bars, anchored to the hull at one end and to each suspension arm at the other, provide
spring action for the suspension arms. An adjustable link, between each compensating idler wheel arm and front road wheel arm,
provides for adjustment of track tension. Shock absorbers at the first, second and sixth road wheels limit the rate of suspension
arm movement at those points. Double volute bumper springs at the first and sixth road wheel arms provide cushioning during
maximum road wheel arm travel. Refer to TM 9-2350-256-10 and TM 9-2350-256-20 for replacement and repair instructions.
Hull and Cab
The hull and cab are constructed of cast armor and armor plate welded into a single unit. Armor is distributed to protect the crew
and equipment against small-arms fire, medium artillery shell fragments and 20-pound anti-tank mines. Hull bottom armor is
equivalent to that of current medium tanks. The hull is equipped with an armored, turret-type cupola that provides a mount for
the caliber .50 machinegun. Additional armament stowed in the cab consists of two M16 or M14 rifles, two submachineguns
and 10 LAW rockets. Four form-fitting, padded, adjustable seats are provided for the four-person crew. Two removable pedestal
stools accommodate two passengers. The two-shot fixed fire extinguisher system may be operated from inside or outside the
vehicle. Two portable fire extinguishers are mounted in the crew compartment. Stowage racks for tools and other equipment
are located at various points inside the cab. Stowage facilities for track sections, cables, tow bars and various recovery tools
and equipment are provided on the outside of the hull and cab. A crew access door is located on each side of the cab. Two
escape hatches in the front roof area are provided for the driver and mechanic. One escape hatch at the rear roof area of the cab is
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