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Chrysler 45RFE: A New Generation Real-Time Electronic Control RWD Automatic Transmission
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 01, 1999 by SAE International in United States
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The 45RFE is a new generation electronically controlled rear wheel drive transmission. It employs real-time feedback, closed-loop modulation of shift functions to achieve excellence in shift quality and to meet severe durability goals. The 45RFE uses no shift valves; all friction element applications are effected with high-flow electro-hydraulic solenoid valves. A unique gear train arrangement of three planetary carriers allows all sun and annulus gears to have identical numbers of teeth and to use common pinion gears in all carriers. This results in substantial manufacturing simplification. The three-planetary system is designed for four forward ratios of 3.00, 1.67, 1.00 and 0.75 and one reverse gear ratio equal to the low gear ratio. A fifth ratio of 1.50 is used mainly in certain kick-down shift sequences for highway passing. A sixth forward ratio, an additional overdrive ratio of 0.67, is available in the hardware. A unique valve body arrangement allows for two manually selectable forward gears and one reverse gear in power-off operation. Torque-based line pressure control and a two-stage pump with independent lubrication feed are provided for improved efficiency and cooling.
A 150,000 mile (241,400 km) truck customer with moderately high engine torque and power requirements was chosen as the design endurance target for this transmission. Early simultaneous engineering, conducted with the transmission, casting, electronic, torque converter, assembly, and supplier groups was a key factor for a successful development program and a remarkable launch in an all-new plant where a “green field” existed only a short time before. A significant contribution to this success is attributable to the entire design being done in electronic files.
|Technical Paper||Chrysler 45RFE a New Generation Light Truck Automatic Transmission|
|Technical Paper||42LE Electronic Four-Speed Automatic Transaxle|
|Technical Paper||The Chrysler A-604 Ultradrive 4-Speed Automatic Transaxle|
CitationMartin, B., Redinger, C., and Dourra, H., "Chrysler 45RFE: A New Generation Real-Time Electronic Control RWD Automatic Transmission," SAE Technical Paper 1999-01-0755, 1999, https://doi.org/10.4271/1999-01-0755.
- Leising, M.B., Benford, H.L. and Holbrook, G.L., “The All-Adaptive Controls for the Chrysler Ultradrive Transalxe”, SAE Paper 890529, Engine Management and Driveline Controls, pp 45-53, SAE SP-788, 1989.
- Martin, B. and Nogle, T., “The Chrysler A-604 Ultradrive 4-Speed Automatic Transaxle”, SAE Paper 890528, Engine Management and Driveline Controls, pp 167-183, SAE SP-788, 1989.
- Leising, M. B., Holbrook, G.L., and Benford, H.L., “Adaptive Control Strategies for Clutch-to-Clutch Shifting”, FISITA Paper 905048, pp 1-11, FISITA 1990.
- Martin, B. and Redinger, C.J., “42LE Four-Speed Automatic Transaxle”, SAE Paper 930671, Automatic Transmissions and Drivelines, pp 61-83, SAE SP-965, 1993.
- Internal communication - First used in 42LE in 1996 model year LH vehicles.