| TorqueFlite | |
|---|---|
 Torqueflite 42RE | |
| Overview | |
| Manufacturer | Chrysler Corporation |
| Also called |
|
| Production | 1956–present[citation needed] |
| Body and chassis | |
| Class | 3- or 4-speedautomatic transmissions or 8-speed automatic |
| Chronology | |
| Predecessor | Chrysler PowerFlite transmission |
| Successor | Chrysler RFE transmission |
TorqueFlite (also seen asTorqueflite) is thetrademarked name ofChrysler Corporation'sautomatic transmissions, starting with the three-speed unit introduced late in the 1956model year as a successor to Chrysler's two-speedPowerFlite. In the 1990s, the TorqueFlite name was replaced with alphanumeric designations, although the latest Chrysler eight-speed automatic transmission has revived the name.
Torqueflite transmissions usetorque converters andSimpson gearsets, two identicalplanetary gearsets sharing a standardsun gear. Chrysler Corporation licensed this gear set fromHoward Simpson in 1955.[1]
The first Torqueflites offered three forward speeds plus reverse.Gear ratios were 2.45:1 in first, 1.45 in second, 1.00 in third, and 2.20 in reverse.
The transmission was controlled by a series of push buttons on the vehicle's dashboard. The buttons were generally located at the extreme driver's side end of the dash, i.e., on the left inleft-hand drive vehicles and on the right in right-hand drive ones. Exceptions included the 1962Dodge Phoenix, a right-hand drive export model sold in Australia and South Africa, which used the standard 1962 U.S.Plymouth Valiant model year instrument cluster assembly, with the transmission push-buttons integrated on the left side.
The button arrangement varied by vehicle model and year; the sequence was reverse, neutral, drive, second, and first, arranged top to bottom with vertically aligned buttons, from left to right with horizontally aligned buttons, and clockwise, starting at the upper left with clustered buttons. The neutral button had to be engaged before starting the engine. In some applications, the button also activated the starter.
A parking lock was not provided until the advent of the aluminum-case Torqueflites in 1960 (standard-duty A-904) and 1962 (heavy-duty A-727), at which point a lever was added adjacent to the push-buttons: Moving the lever to the "park" position placed the car into neutral and engaged a lock pawl on the transmission's output shaft. Moving the parking lever from the "park" position unlocked the shift buttons to select a driving range. The buttons were replaced by conventional steering column- or floor-mounted shift levers in all automatic Chrysler-built vehicles for the 1965 model year. Floor shift levers were available in some 1964 models. The levers always used the P-R-N-D-2-1 sequence.
Like the operation ofGeneral Motors'Hydramatic transmissions, Torqueflites start in first gear when the drive or second position is selected. This contrasts with vehicles equipped with automatic transmissions fromFord andBorg-Warner, which begin in second rather than first if the second position is selected.
For 1962, a canister-style fluid filter was installed in the cooler line. For 1964, the canister filter was eliminated, and an efficientDacron filter replaced the transmission's internal intake screen. Fluid life starting in 1964 was extended from 12,000 mi (19,000 km) to 50,000 mi (80,000 km), justifying the deletion of the drain plug from the oil pan.
For 1966, the twin-cable shift and park control mechanism (a holdover from the push-button operation) was replaced by a solid shift control linkage consisting of a series of pushrods, rotating rods, and levers. The rear pump was eliminated, which simplified and reduced the cost of the transmission but rendered push-starting impossible. Chrysler engineers reasoned that improved electrical and fuel systems reduced the need for push-starting vehicles, and safety concerns outweighed the benefits of doing so. The gated shift quadrants also permitted the deletion of the reverse safety blocker valve, which, in TorqueFlites made through 1965, had shifted the transmission harmlessly into neutral if the driver selected the reverse position while the vehicle was moving forward at speeds above approximately 3 mph (4.8 km/h). With the elimination of the rear pump, the oil filter was designed with a single oil port.
In 1968, part-throttle downshift functionality was added to A-904 transmissions used with six-cylinder engines. This feature permitted the transmission to shift from third to second gear in response to moderate accelerator pressure. Previously, an automatic 3-2 downshift occurred only if the driver pressed the accelerator to the floor. This change was made to maintain acceptable in-town performance with taller final-drive ratios in the rear axle — 2.76:1 rear axle gears were being furnished in applications previously equipped with 2.93:1 or 3.23:1 gearsets. Part-throttle downshift functionality was extended to V8 A-904s in 1969 and to most A-727 transmissions in 1970 and 1971.
Starting in 1978, most Torqueflite transmissions were equipped with a lockup torque converter clutch, which mechanically connected the converter's impeller and turbine, thereby eliminating slip and improving highwayfuel economy. This addition required the removal of the torque converter drain plug.
For 1980, a wide-ratio gearset was introduced for the A904, A998, and A999, featuring a 2.74:1 ratio in first gear, 1.54 in second gear, and 1.00 in third gear.
Since 1962, a version of the Torqueflite was an available option or standard equipment, depending on model and year, on rear-wheel-drive Chrysler products:Plymouth,Dodge,DeSoto, Chrysler, andImperial.[2] When installed in light-duty Dodge trucks and vans, the transmission was marketed asLoadFlite.[2]
The Torqueflite replaced Borg-Warner automatics inAmerican Motors Corporation (AMC) cars beginning with the 1972 model year, and AMC marketed them asTorque-Command.[3] After 1979, AMC discontinued offering the Hydramatic inJeeps to join the rest of AMC's models.[4]
Other automakers using the Torqueflite includedInternational Harvester,Maserati Quattroporte,Monteverdi (automobile), andBristol, as well as several brands of light and medium-duty trucks and panel vans.[5][6]
In the 1990s, the transmissions were renamed. However, the original Torqueflite design remained the basis of many Chrysler-designed and built transmissions through 2007 (and FWD transaxles through 2000).
Torqueflite transmissions and transaxles made through 1991 were assigned arbitrary engineering designations consisting of the letter "A" followed by three digits. The 1992 and later units have four-character designations in which the first through fourth characters indicate, respectively, the number of forward speeds, torque capacity, drive type or transaxle orientation, and control system:
| Forward speeds | Torque capacity | Drive type | Control |
|---|---|---|---|
3 or 4 | 0 (low) to 9 (high) | R (Rear wheel) T (Transverse) A (All-wheel) | H (Hydromechanical) E (Electronic) |
The original TorqueFlite was designatedA466, with acast iron case, separate iron converter housing, and no parking pawl.
The A466 was replaced in 1962 with theA727 (later renamed36RH and37RH), with a one-piecealuminum case to reduce weight by about 60 lb (27 kg). This was initially referred to in consumer-oriented publications as the "TorqueFlite 8" to differentiate it from the A904. The A727 incorporated a parking pawl, with the sole exception being that for 1962 the Chrysler, Imperial, and Dodge 880 (based on a Chrysler Newport) A727s had an extension-mounted drum parking brake instead of a parking pawl. Compared to the early cast-iron transmissions, many and various internal improvements were featured, and it used a 10.75 in (27.3 cm) or 11.75 in (29.8 cm) torque converter. The heavier-duty A727 Torqueflites became — and remain — wildly popular fordrag racing,off roading, andmonster truck applications because of their controllability, reliability, ease/cheapness of repair, and brute strength. There are unique bellhousing bolt patterns for the small block "A" and big block "B" engine versions of this transmission and forAmerican Motors (AMC) and Jeep applications.
Gear ratios:
| 1 | 2 | 3 | R |
|---|---|---|---|
| 2.45 | 1.45 | 1.00 | 2.20 |
TheA518, later renamed46RH (hydraulic controlled governor pressure) and46RE (electronic controlled governor pressure), is an A727 derivative withoverdrive, in the A500 ilk. Starting in 1990, it was used in some trucks and vans. The overdrive fourth gear ratio is 0.69:1.
Gear ratios:
| 1 | 2 | 3 | 4 | R |
|---|---|---|---|---|
| 2.45 | 1.45 | 1.00 | 0.69 | 2.35 |
Applications:
TheA618, later renamed47RE (electronically controlled governor pressure) is a heavier-duty version of A518, also known as the 46RE (which also has electronically controlled governor pressure, versus the earlier RH version, which was hydraulically controlled). It was used in trucks and vans starting in the mid-1990s. While currently used with some internal changes such as the move from aluminum to steel planetary carriers and an increase in the number of clutch plates when coupled to the 5.9 L Cummins Turbo-Diesel and the 8.0 L V-10 applications, it is a 727 with overdrive and more robust internal parts. It has an input torque rating of 450 lb⋅ft (610 N⋅m). The48RE is an electronically governed, ECU-controlled, four-speed heavy-duty overdrive automatic transmission, that is stronger than its predecessor, the 47-series. The 48RE was introduced in 2004 to 3rd gen ram pickups with the 5.9 cummins, or the v10, some 03 and early 04 trucks still were equipped with 47RE units, and then came a 48re which still used a TV cable, and then from 04.5 to 07 the 48re was fitted with a TTVA motor (transmission throttle valve actuator) which eliminated the need for a mechanical TV cable. 48re units had the highest volume pump out of any of its predecessors, using a 10 lobe design with tighter clearances (.003"-.005") versus the 47REs 11 lobe design for additional holding ability. More volume was on tap to be circulated through the larger cooling circuit. with the higher than ever low end cummins torque, the direct drum was bigger to allow 5 .085" frictions and 5 .084" steels, the forward drum is in fact made bigger (deeper) to make room for the 5th direct friction/steel, the 48s forward clutch frictions switched from a 64 tooth to a 93 tooth inner spline count, 6 pinion, steel planets were introduced with more robust thrust washers backing them, the overdrive housing was slightly enlarged in the parking mechanism areas to allow the bigger parking rod and pawl mechanism. Most importantly the valvebody introduced the ability to have 2nd gear tcc lockup in manual second. A handful of other enhancements, part throttle 3rd gear tcc lockup was a big quality of life enhancement.
The base design from the original Torqueflite remains essentially unchanged. The addition of a two-speed output shaft (overdrive unit) that is bolted to the back of the three-speed transmission has only two ratios: direct (1:1) and overdrive (.69:1). While lubrication to the overdrive unit was a challenge early on, this was overcome with factory improvements or aftermarket valve body kits. The overdrive planetary has six-pinion gears (unlike the five-pinion used with the A518 used with the Cummins turbodiesel), which is often used as an aftermarket replacement for the stock four-pinion planetary used with the lighter duty transmissions.
Gear ratios:
| 1 | 2 | 3 | 4 | R |
|---|---|---|---|---|
| 2.45 | 1.45 | 1.00 | 0.69 | 2.21 |
Applications:
For standard-duty applications in smaller and lighter vehicles withsix-cylinder or small V8 engines starting with the 1964-1/2 273, the compactA904 (later30RH) was introduced in 1960. This transmission used a 10.75 in (27.3 cm) torque converter. A smaller version of this transmission was also used in theDodge Colt/Plymouth Champ cars made by Mitsubishi in Japan. This smaller transmission used a 10 in (25 cm) torque converter.
There are unique bellhousing bolt patterns for the Chrysler Slant-Six, small block V8, and AMC versions (both the six and V8s), including the Chevrolet V8 bellhousing pattern when used with the GM Iron Duke, which was the base engine in some 1980–1983 AMC and Jeep products (this bellhousing pattern is not commonly found since transmission cores are usually sought after fordrag racing in building a Powerglide or TH200 derivative using THM2004R internals inclusive of a modified torque converter front face and/or torque converter adapter ring allowing the use of the TorqueFlite bolt pattern to a GM flexplate), and a GM 60 Degree V6 bolt pattern when used with the GM 2.8 LLR2 of this transmission.
Uses:
TheA998, later renamed31RH was a medium-duty, narrow or wide-ratio version of the small-frame A904 transmission for use with medium-power V8 engines and the3.9 L V6 engine. It was equipped with four direct friction plates. This transmission differed from the A904 by having a reinforced case and internals. Narrow ratios are 2.45/1.45/1.00:,1 and wide ratios are 2.74/1.55/1.00:1.
Uses:
TheA999 (later renamed32RH) was a heavier-duty, wide-ratio version of the small-frame A904 transmission for use with medium-power V8 engines and the 3.9 L V6 engine. It was equipped with five direct friction plates. These automatics had lower first- and second-gear ratios, allowing the lower-powered engines to provide better acceleration without sacrificing highway fuel economy. They were frequently used today in drag racing.
Uses:
TheA500, later renamed40RH and42RH (hydraulically controlled governor pressure) and40RE,42RE,44RE (electronically controlled governor pressure, 1993-up), was an A904 derivative used in trucks and vans. Introduced in the 1988 model year on a limited basis, it was the first light-duty Chrysler four-speed automatic and was placed behind the 3.9 L and 5.2 L engines for light-duty purposes. Forward direct clutch drum (same as the A998) usually has a four friction disc pack – an A999 forward direct clutch drum with the five friction disc pack does interchange. A bolt-in low/reverse overrun clutch assembly (shared with the A904 derivatives manufactured after 1988) uses a roller clutch, which is shared with the GM THM200 and THM2004R. Much like the later production A904 with a wide ratio gear, a double wrap low-reverse band is used. An extension housing mounted (New Process built) overdrive unit was bolted to the rear of the case to provide a total of four forward speeds; the extension housing and its internals interchange with the 46-48RH/RE (A518/618) – when overhauling the overdrive unit transmission rebuilders usually would use replacement parts from the A518/618 overdrive section since the A500 internals are light duty e.g. number of friction discs and thick pressure plates.
The overdrive housing (RWD/2WD) uses an output shaft yoke commonly shared with the A727 and its later derivatives, except for the A618/48RE. Electronic governor pressure was phased in during the middle of the 1993 model year, where it was renamed as the A500SE – Jeep Grand Cherokees equipped with the 4.0L used the A500SE/42RE since the middle of the 1993 model year replacing the AW4. Oil pans used with the A500SE/42RE are similar in design to the one used in the A500, with a clearance area for the shift solenoid. The pan and filter were updated during the 1998 model year with some Dodge applications, which have a deeper oil pan and a redesigned oil filter that is held with two valve body screws (the single oil port filter does interchange with the older A500 and A904 derivatives along with the oil pan). This transmission was replaced by the 42RLE in 2004.
Gear ratios:
| 1 | 2 | 3 | 4 | R |
|---|---|---|---|---|
| 2.74 | 1.54 | 1.00 | 0.69 | 2.21 |
Applications:
The A404, A413, A470, and A670 arefront wheel drivetransaxle derivatives of the A904 Torqueflite.
In the late 1970s, Chrysler designed theA404 TorqueFlite three-speed automatic transaxle for its front-wheel driveDodge Omni andPlymouth Horizon subcompact cars. This transaxle would be upgraded in the 1980s into theA413 andA670 units, which were progressively heavier-duty, for Chrysler'sK-cars and their derivatives, including the minivans. The four-speedUltradrive electronic four-speed automatic transaxle would eventually replace it. Still, the three-speed lasted for more than a decade after the 1989 debut of the four-speed unit.
The light-duty A404 was used with the smalleststraight-4 engines from Chrysler, commonly the 1.7 LVolkswagen unit.
The A404 was strengthened to become theA413 (later31TH) in 1981. This was used with Chrysler's 2.2 and 2.5 LK-car engines. It was available both with and without alockup torque converter.
Applications:
TheA415 was developed for the 1.6 LSimca 1100 engine, but was not released for series production in the U.S. It was used in Europe, in the Talbot Simca, 1510, and Solara.
TheA470 was a strengthened version of the transaxle used with the 2.6 LMitsubishi Astron engine in theK-cars from 1981 until 1985, andminivans from 1984 through 1987.
The highest-specification three-speed transaxle was theA670. It was used with the 3.0 LMitsubishiV6 engine in Chrysler's cars and minivans from 1987 to 2000.
Gear ratios:
| 1 | 2 | 3 | R | Final |
|---|---|---|---|---|
| 2.69 | 1.55 | 1.00 | 2.10 | 3.02 |