Toyota Transmissions
We are just starting this page; more is coming.
2019-2021 Corolla transmissions
The new K120 CVT is a continuously variable transmission; it cleverly combines the usual bands with a special launch gear (the world’s first launch gear in a passenger-car CVT) as well, because CVTs are not efficient in lower gear ratios. When drivers start, they will have “gear drive,” avoiding a moment of sluggishness and wasted power. It moves from gear to belt drive after launch, so the belts can be retuned for higher gear ratios, increasing the range.
Combined, the two systems bring an excellent, class-leading range of 7.5 — similar to much more expensive nine speed automatics. Reducing the torque load of the belt meant that the belt and pulley could be smaller, increasing shift speeds. The transition is a little awkward for some drivers, but one gets used to it.
The six-speed “iMT” (intelligent manual transmission) automatically matches engine revs on downshifts for greater smoothness and lower emissions. The new gearbox is also 15 pounds lighter (at 88 pounds) and shorter (by 0.94 inches).
A131L, A240E, A241E, and A245E automatics
1993 Corollas with the 4A-FE engine kept the old A131L three-speed automatic transaxle, but a new four-speed A245E automatic transaxle was used with the 7A-FE engine.
The A240E was developed for the 1989 Toyota MR2 and upgraded to the A241E in the 1993 MR2; engineers worked to make it smaller and lighter for the Corolla, whose power-handling needs were not as severe as the MR2’s. The result was the A245E. It kept the four speeds and lockup torque converter; the latter, developed originally by Chrysler some years earlier, provided a direct mechanical link between engine and rear wheels, avoiding the waste of using oil to transmit power. Both A240E and A245E transmissions were electronically controlled (hence the “E”) and quite advanced for their time.
| Transaxle Type | A131L | A245E |
|---|---|---|
| Engine Type | 4A-FE | 7A-FE |
| 1st | 2.810 | 3.643 |
| 2nd | 1.549 | 2.008 |
| 3rd | 1.000 | 1.296 |
| 4th | - | 0.892 |
| Reverse | 2.296 | 2.977 |
| Counter Gear Ratio | 0.945 | - |
| Differential | 3.526 (3.722 opt in USA) |
2.821 (had been 2.962) |
| Trans fluid | 5.5 l (5.8 qt) | |
| Trans fluid type | DEXRON® II (GM compatible) | |
| Differential fluid | 1.4 l (1.5 qt) | 7.6 liters (8.0 qt) |
Specific changes made to create the A245E from the A240E were:
- The counter drive gear, supported at both ends in the A240E, was supported at only one end; the second speed sensor and the sensor rotor were dropped.
- The second gear coast brake position and valve body mounting area were changed to lower the height.
- The accumulator and the oil passages were changed to improve the shift feel.
- The throttle valve opening was divided into 32 steps to improve fuel efficiency.
The planetary gear units were similar, and were modified to work better with the 7A-FE.
| A245E | A240E | |
|---|---|---|
| Forward Clutch Discs | 4 | - |
| Direct Clutch Discs | 3 | - |
| Underdrive Direct Clutch Discs | 3 | 4 |
| Second Coast Brake Band Width | 25 mm | - |
| Second Brake Discs | 3 | - |
| First and Reverse Brake Discs | 6 | 5 |
| Underdrive Brake Disc | 3 | - |
| No. 1 One-Way Clutch Disc | 18 | - |
| No. 2 One-Way Clutch Sprags | 20 | - |
| Underdrive One-Way Clutch Sprags | 30 | - |
| Front Sun Gear Teeth | 39 | - |
| Front Pinion Gear Teeth | 16 | - |
| Front Ring Gear Teeth | 71 | - |
| Rear Sun Gear Teeth | 27 | - |
| Rear Pinion Teeth | 18 | - |
| Rear Ring Gear Teeth | 62 | - |
Toyota wrote: “The accumulator consisted of C1, C2, C3, B2 and B4 as in the A240E. While the C1 accumulator piston of the A240E was activated only by the spring tension, the C1 in the A245E was activated by the spring tension as well as the back pressure, as were C2, C3 or B2. Lenghthening the stroke of all accumulator pistons reduced the shift shock.”
Electronic Control for the Transmissions
The electronic control system for the A241E (1993 MR2) and A245E (1993 Corolla) were similar except, as noted, the second speed sensor was dropped (so the #61 diagnostic code was removed) and the throttle valve opening was divided into 32 positions, up from eight, for better shift control. Diagnostics were the same for the two transmissions.
C50 and C52 manual transmissions (1993-1997) and associated clutches
These likely continued long past 1997. We will determine the true start and end dates later.
The C50 and C52 manual transaxles carried forward to the 1993-97 models; the shift lever moderating mechanisms from the old four wheel drive models was made standard on the front wheel drive cars for a better feel. The C52 had launched in the 1991 Corolla with the 4A-GE engine. The same transmissions were used in other cars with the 4A-FE and 7A-FE engines.
The dry, hydraulic single-plate clutch was used in past cars, but added a resin-washered damper (first used in the 1993 MR2 and 7A-FE equipped Corollas) to reduce noise. When used with the 7A-FE in the Corolla, a turnover device in the clutch pedal assembly reduced pedal load, unless drivers had antilock brakes or the theft deterrent system. The mechanism for cutting load was an overcenter plate and a tension-type coil spring.
| 1993-1997 | 4A-FE, 7A-FE engines | |
| Clutch | Dry single plate with diaphragm spring, hydraulic operation | |
| Cluch Cover | Diaphragm spring turnover type, 215 mm (8.5 inches) | |
| Clutch Disc | 212 x 140 x 3.5 (8.35 x 5.51 x 0.14 inches); 199 cm2 (30.8 square inches) | |
| Master Cylinder | Conventional, 15.87 mm diameter (0.62 inches) | |
| Release Cylinder | Non-adjustable; 20.64 mm (0.81 inches) diameter | |
The prior generation Corolla’s “type A” shift lever moderating mechanism continued in 1993-onwards Corolla wagons; a new one, type B, was used in sedans. The construction was updated but both had similar operation. The detent shaft in type A was replaced by the shift lever in type B.
| C52 Gear Ratios and Capacities | |
| 1st | 3.545 (3.166 with 7A-FE) |
| 2nd | 1.904 |
| 3rd | 1.310 |
| 4th | 0.969 |
| 5th | 0.815 |
| Reverse | 3.250 |
| Differential ratio | 3.722 |
| Oil Capacity | 2.6 liters (2.7 US quarts) |
Oil Viscosity |
SAE 75W-90 |
| Oil Grade | API GL-3, GL-4, or GL-5 |
Gear ratios, 1977 Corolla five-speed
3.59, 2.02, 1.38, 1.00, 0.86; all gears synchronized.