|Product type:||Transmission & Drives|
The XTG411-4, -4B and -5 transmission models were developed by Allison Transmission and derived from the transverse engine-mounted XTG411-2A crossdrive transmission. The XTG411-2A development began in the 1960s and it was in production for the US Army M109 series Self-Propelled Howitzer, M578 Light Recovery Vehicle and the M992 Field Artillery Ammunition Support Vehicle programmes. Requirements for higher power levels and increased mobility of similar tracked vehicles in the 1980s evolved successfully into these enhanced transmission models.
The XTG411-4 transmission models are for engine powers up to 650 ghp (485 kW). The XTG411-4 transmission has been in production since 1987 for the Textron Marine and Land Systems Stingray Light Tank, Achzarit heavy infantry combat vehicle used by the Israel Defence Force and based on a T-55 tank chassis, the M109A6 Self-Propelled Howitzer and the M992A2 Field Artillery Ammunition Support Vehicle. Vehicle installations have also been completed for repowering Russian/Chinese T-series and French AMX-30 MBTs.
Transmission improvements have incorporated extended life clutch plate materials, increased braking capacity, optimal torque converters and optional engine flywheel housing adaptations. Allison Transmission have developed an upgrade kit which allows the XTG411-2A to be upgraded to the XTG411-4 standard.
The XTG411-4B transmission model is a fully automatic shifting version of the XTG411-4 power shift transmission. The adaptation of the off-highway commercial Allison Transmission Electronic Controls removes the driver's responsibility for shifting by use of a microcomputer. Shifts are based on throttle position, transmission output speed, shift selector position and the programmed shifting logic. In addition to the flexible programming for various vehicle and engine requirements, the Electronic Controls offers self-diagnostics for simplified troubleshooting and inhibits abusive operation for extended transmission life. The transmission controls have completed a 6,434 km XM975 vehicle durability test and are part of the M109 RISE test programme for the US Army. Previous vehicle testing confirmed a fuel saving when operating the vehicle over terrain requiring frequent shifting to maintain vehicle speed.
The XTG411-5 transmission model is for engine powers up to 850 ghp (634 kW). Allison Transmission Electronic Controls, high-strength shaft materials and additional braking capacity have been incorporated for the higher power and vehicle requirements beyond the XTG411-4 ratings.
TheXTG411-5 is also used in repower packages for the Russian T-54/T-55 series of MBTs.