Allison Transmissions

Automatic Models HT 740 up to 445 nhp (332 kW)

Net input power (max).............................445 hp (332 kW)
Input speed range................................1900 - 2400 rpm
Net input torque (max)......................1435 lb ft (1946 N·m)
Vehicle weight (max)............Up to 80,000 lbs (36,287 kg) GVW
                                 and 130,000 lbs (58,967 kg) GCW    

Direct..............SAE 1 flywheel housing with flex plate drive
Remote.....Converter housing side pads, and rear housing top pad    

Type..........................Single-stage, 3-element, polyphase
Stall torque ratio.........TC 487-1.50; TC 488-1.70; TC 497-2.72;
                           TC 470-2.83; TC 495-2.39; TC 496-1.78;
                                        TC 498-2.45; TC 499-1.91
Automatic lockup clutch..........Effective in all forward ranges
                          or effective in 2nd through 4th ranges
                                       – depending on model used    

Type.........................Constant mesh, spur type, planetary

         Range                                  Ratios*:
         First...................................3.69:1
         Second..................................2.02:1
         Third...................................1.38:1
         Fourth..................................1.00:1
         Reverse.................................6.04:1
           * Gear ratio does not include torque converter ratio.    

Converter driven (SAE 6-bolt)
Location................10 o'clock position (as viewed from rear)
Drive gear ratio............................1.00 x turbine speed
Drive gear rating.................300 lb ft (407 N·m) continuous; 
                                400 lb ft (543 N·m) intermittent

Engine driven (optional) (SAE 8-bolt)
Location....converter housing: one at 1 o'clock position and one
                      at 8 o'clock position (as viewed from rear)
Drive gear ratio.......1 o'clock position – 1.35 x turbine speed;
                       8 o'clock position – 0.84 x turbine speed
Drive gear rating.................200 lb ft (149 N·m) continuous; 
                                260 lb ft (194 N·m) intermittent    

Oil type..........................................Dexron II®, C4
Capacity 
       (excluding external circuit)...7.5 U.S. gals (28.5 liters)
                                                 (w/std. oil pan)
Filter..................................External, remote mounted 
Cooler............................................Remote mounted 

(Filter and Cooler not furnished on transmission assembly but is supplied
 by vehicle manufacturer.)    

                                                             
Length..........................................37.4 in (950 mm)
Width...........................................21.7 in (552 mm)
Height..........................................26.6 in (675 mm)
Weight (dry)..........................840 lbs (381 kg) (approx.)

+NOTE: Vocational ratings may vary by vocation.     

	Designed for use with diesel engines up to 445 nhp (332 kW). Four forward ranges and one reverse. This transmission model is best suited for medium- and heavy-duty trucks and buses.
	Clutches are multidisc design, oil-cooled, hydraulically-operated, and self-compensating for normal wear. Spur-type planetary gears are designed for strength, quietness, and long life.
	Automatic lockup clutch, throttle-modulated for maximized fuel economy and enhanced engine braking. Automatic upshifting and downshifting within each drive range. Built-in inhibitors prevent downshifts or shifts into reverse unless vehicle speed is within an acceptable range.
	The Allison three-element torque converter provides smooth, shock-free operation. A choice of converters permits matching the HT 740 to a wide variety of engines.
	Converter-driven power takeoff drive on right side of transmission (as viewed from the rear) is standard. Design is SAE 6-bolt.
	Optional engine-driven power takeoff is available in two locations - upper right and lower left sides, as viewed from rear. Design is SAE 8-bolt.
	Provisions for neutral start switch, reverse signal switch, SAE regular-duty thread-type speedometer drive, electronic speedometer drive, and parking brake.
	7.0 inch oil pan is standard. Optional 6.0, 4.5 and 8.5 inch pans are available when ground clearance or heavy duty operation dictates their use.

	Dump Truck
	Refuse Hauler
	Lowboy Truck
	Hook & Ladder Truck
	Transit Mixer
	Fire Truck
	Logging Truck
	Rear Loader (Refuse)
	Agricultural
	Motorhome
	Construction Equipment Hauler
	Wrecker (Tandem Axle)
	Public Utility (All Wheel Drive Tandem Axle)
	Other applications are available.