Chrysler, Dodge, Plymouth, Jeep, and DeSoto Transmissions
Automatic transmissions in roughly chronological order
- Hy-Drive (2 speeds)
- Powerflite (2 speeds)
- Fluid Drive (torque converter)
- M6 and M4 (semi-automatics)
- TorqueFlite (3 speeds) - the legend! We have a detailed, well-written article with many photos describing how the TorqueFlite works, showing modifications, and discussing relatively common problems and how to solve them.
- A-413 (3 speeds) front-drive automatics used front-wheel-drive cars. Derived from the TorqueFlite basic design.
- Four-speed automatics:
- Important maintenance and repair information
- 41TE, 41TES, and 40TES description and information
- 42LE - modifications from 41TE
- Some four-speed transmissions gained variable line pressure (VLP) for 2006 (see separate section below).
- Five speed automatics:
- 45RFE: has two overdrive ratios and uses 4 ratios in its normal shift sequence. See the last part of the article at this page.
- 545RFE: has two overdrive ratios and uses 5 ratios in its normal shift sequence. When you floor the throttle at highway speeds it will downshift to the taller numerical second gear ratio to help smooth out the downshift. Starting in 2009, the 545RFE allowed drivers to select the highest gear the transmission would shift to (for towing, hill climbing, and hill descent).
- Some vehicles (including Grand Cherokee Hemi and 300C/Charger/Magnum with five-speed) use a Mercedes five-speed automatic, the W5A580. A Mercedes tech told us that the last three numbers are the amount of torque it can handle (in Nm), giving it a capacity of 427 lb-ft of torque.
- 62TE Six speed automatic
- The automatically-shifted manual transmission: coming to a Dodge near you?
- Hybrid-electric transmission: see end of page.
Manual transmissions (incomplete)
- (We need your help to augment this section.)
- Front-drive Getrag manual transmissions: 1980s, 1990s
- Brief Neon automatic and manual transmission info
- Details on 2.2 TBI and 2.2 Turbo III transmissions
- The early Imperials page has a detailed description of the 1930s four-speed manaul.
Performance, repair, and racing issues
- Shift kits and manual valve bodies
- Why you need a clutch shield for racing
- Upgrading to a manual transmission (from an automatic - front wheel drive)
- Transmission mounts (front drive)
- Shifter cables - 1960s, 1990s
Variable line pressure (VLP) automatic transmissions
Some four-speed transmissions gained variable line pressure (VLP) for 2006; VLP was phased in throughout the line. The VLP transmission frequently adjusts its internal fluid pressure to reduce parasitic losses from the pump and hydraulic system, increasing gas mileage and lengthening the transmission lifespan. For 2006, transmissions connected to the 3.7 liter V6, as well as the 2.7 engine in the LX series, got VLP. The use of variable line pressure allowed for numerous other improvements, greatly increasing the transmission’s efficiency.
Chevrolet transmissions?!?
Randle Blankenship wrote: There was a time in the early to mid 1950s when GM Hydramatics were used not only in GM cars, buses, trucks, and military vehicles, but Lincoln, Nash, Hudson, Kaiser, and Willys cars. The sound of their coming and going was distinctive. Add to that list some Dodge postal delivery trucks! I assumed the vehicles to be 1954 or 1955 models. They were right hand drive, with the shift lever sprouting from the left side of the steering column. The shift quadrant was marked R Lo Dr N ! I had an opportunity to observe one of these closely in a repair shop in the late 1950s, and confirm that it was indeed a four speed truck Hydramatic coupled to a Dodge Six engine. The same vintage International postal trucks were using 3 speed Borg Warner automatics. At the time I knew of no consumer type Dodge truck being offered with any kind of automatic, though some earlier Dodge pickups had optional fluid drive.
(Chevrolet transmissions return to Chrysler vehicles as part of the following hybrid system.)
Hybrid-electric transmissions
General Motors, Chrylser, and BMW have developed a two-mode transmission/motor designed for hybrid-electric vehicles which should increase the gas mileage of full-sized SUVs by 15%-25% (the 25% figure includes GM's cylinder-cutoff system which is similar to Chrysler's MDS). It will be an option in the 2008 Dodge Durango as well as big Chevy and Cadillac trucks and Mercedes and BMW cars. GM will actually build all the transmissions in a new plant near Baltimore, according to an Autoweek report. It can be programmed for either gas mileage or performance (the Prius hybrid is programmed for mileage, the Highlander hybrid for performance). The system looks like a regular rear-drive transmission, but has two electric motors inside; one is used for low speeds, the other for high speeds. A similar device is being developed for front-drive cars; its key advantage over competing systems is that it requires little redesign of the rest of the car, simply bolting into place where the standard automatic would normally go. It can even be used in four wheel drive vheicles. The transmission is due in the fourth quarter of 2007. The automatic-transmission part (which is used for transmitting gas-engine power) appears to be a CVT.
