Toyota automatic gearbox fault diagnosis and maintenance. （I）
Toyota automatic gearbox fault diagnosis and maintenance (on)
"Car to the front there is a road, a road there Toyota", which is Toyota’s well-known quote, all types of Toyota Motor economy, for the advantages and easy maintenance by the majority of automotive consumers love, which makes Toyota car ownership in China showed a steady growth trend. In the automatic transmission, Toyota usually produced in the automatic transmission AW for 方便 us to understand, grasp and maintenance, from the current start, we have automatic transmissions for Toyota structural characteristics of improved diagnosis Fangfa Cuoshi and Gu Zhang such detailed analysis and explanation.
1, Toyota cars automatic transmission models and structural characteristics:
(A), transmission model
In the Toyota car, used automatic transmission form more of their models are mainly: A130L, A131 (L), A132 (L), A140E / L, A141E, A142E, A240E / L, A241E/L/H, A340E / H / F, A341E, A342E, A540E / H, A541E, A650E, A750E / F, A761E, A440F, A442F, U140E / F, U151E / F, U241E, A245E, A246E, U341E, U540E, U541E so.
Toyota automatic transmission automatic transmission models and generic models, as have more specific meaning, understanding and ownership of a specific meaning, then we can start with models that some characteristics of transmission to the back of our maintenance work basis. Below to "A541E", for example, automatic transmission on the Toyota model to explain the meaning of:
A - Representative Automatic Transmission 5 - Drive Type :1,2,5 - precursor ,3,6,7 - after flooding
4 - Number of forward gears :3 - 3-speed, 4 - 4-speed ,5 - 5-speed 1 - Transmission of the production number
E - Type: electronically controlled with lock, no "E" - full hydraulic control; L - torque converter with lock, H or F - four-wheel drive
Special Note: The above automatic gearbox, A340H, A340F, A540H type behind it are omitted "E", they are electronically controlled automatic transmission, and with a locking clutch; A241H, A440F, A442F Automatic Transmission box, then have omitted the "L", but all with a locking clutch. The improved automatic transmission, an increase of only lock the clutch or the driving wheel of the number, without making other changes to the original model only after the notation "L", "F" or "H", the original model unchanged.
(B) the structural characteristics
1, Toyota automatic transmission is the first use of electronic control system of automatic transmission, so the less pure transmission fluid control, and now more generally the use of electronically controlled half or full electronic control automatic transmission, semi-electric controlled automatic transmission by a main hydraulic throttle pull adjustment (Figure 1), which only emphasized hydraulic pull, do not adjust shift points.
2, in the Toyota automatic transmission, the planetary gear they use a Simpson planetary gear mechanism, which is characterized by sharing the sun wheel, the overall structure is relatively simple, this will help beginners to understand and analyze the transmission of the transmission line, and control over their maintenance methods.
3, Toyota four-speed automatic transmission by a speeding planetary line and a Simpson planetary line composition, general after the drive transmission (eg: A340E, A341E, etc.) speeding planetary line generally installed in front of Simpson gear mechanism, the precursor transmission ( such as: A140E, A540E, etc.) planetary line speed gearbox is mounted on the rear (behind the Simpson planetary line).
4, for the older models of the Toyota electronic control automatic transmission, the majority of the valve body has three solenoid valves, including two shift solenoid valve and a locking valve. When the transmission fails to enter safe emergency mode, the electronic control system will usually lock the gearbox in Si Dang, that gearbox lock Sidang.
5, Toyota Automatic Transmission in the mechanical structure, the general design of the 2-speed manual band brake (Figure 2), so when the gear lever with manual 2 block, vehicles with engine braking effect.
6, Toyota automatic transmission has a torque converter lock function.
Figure 1 electronic control gear of the throttle pull only the main oil pressure regulator designed to manually map 2 2 block from the engine brake with brake function
Second, overexertion, equipment and transmission line analysis:
Toyota automatic transmission model more, but the planetary gear mechanism and the transmission line with the general, where internal structure is more typical A340E automatic transmission, for example, its force on plant and transmission line are explained. The planetary gear transmission with a single Top Gear star (ie speeding planetary line) and a Simpson planetary line formed in the Simpson planetary line, there is a common sun gear, the sun wheel and the front ring gear can be separately or simultaneously as the power input device, front and rear ring gear planet carrier as a single entity as the output device, the rear planet carrier to the independence movement, with 2 one-way clutch, low reverse gear brake connection, when the brake at low reverse gear the formation of low-speed gear and reverse gear. The power transfer diagram in Figure 3 (Component Description: 1 - speed brake block 2 - speed gear clutch 3 - speed one-way clutch gear 4 - 2 block with hand brake 5 - high-speed block / reverse gear clutch 6 - 7 forward gears clutch - two one-way clutch block brakes 8-1 No. 9 - low block / reverse gear brake one-way clutch No. 10-2).
Blocking force on the role of the device are as follows：
Figure 3 A340E A340E power transmission line, automatic transmission, the block diagram of force on device function table
Component description: C0-C1-forward speed gear clutch gear clutch gear clutch C2-direct gear brake B0-speed manual 2 block B1-B2-2 with brake block brake B3-low speed reverse gear brake block one-way clutch F0-F1 -1 No. 号 one-way clutch F2-2 one-way clutch
Force on device components from the above worksheet can be seen in the structural design of gearbox which has the engine braking effect, when the gear shift in manual 2 block, 2 block with a hand brake to work on a shared fixed Simpson planetary line sun wheel, so when the vehicle under a long steep slope or when the gear lever with manual sliding block 2 can produce engine braking effect, thereby enhancing the braking effect. When the shift lever in "D" position, the hand brake with 2 block is not involved, because the speed of vehicles driving wheels when going downhill faster than the input speed, 1-way clutch slip, so in this vehicle without the engine brake effect.
The following 2 2 block to block manually, for example, to analyze the transmission line as:
2 block with manual gear shift, power passed from the input shaft speed planetary line planetary gear, as 2 block block Clutch speeding, speeding one-way clutch gear lock, will speed planetary line with a whole planet for speeding row ring gear and the forward gears and clutch hub directly connected into one block, then forward gears Clutch, Power by the forward gear clutch input to the Simpson planetary gear mechanism of the front ring gear, because of manual block 2 with brake (when Vehicle engine braking effect generated when sliding) and the second block brake at the same time involved, the 1st one-way clutch lock, fixed share the sun wheel, so power from the front planet carrier by the output shaft to the main reducer.
Third, the new gearbox to improve older Description:
We have mentioned earlier, Toyota produced mainly AW automatic transmission, and AW is the world’s major automotive automatic transmission is one professional manufacturer, after years of development, the automatic transmission are mainly the following aspects of the improvements:
1, before the advent of the electronic control transmission, hydraulic controlled automatic transmission Toyota few, mainly: A130L, A131L, A132L, A140L, kind of transmission of the torque converter fluid control lock function has the main applications 80 years ago on the old Toyota cars, has now been eliminated.
2, 1982, electronically controlled automatic transmission first appeared in the Toyota, and used in cars, on the crown; in 1983, followed by Toyota A140E transmission electronic control came and installed in the four-cylinder Camry sedan, it has to automatically Transmission pushed the development of a new high. This gearbox has a very high practical value, until now used in the smaller displacement cars on the Toyota Camry.
3, for the old models of the Toyota electronic control automatic transmission (such as: A140E, A340E, etc.), generally only three solenoid valves, one for torque converter lock, the other two work for the shift gearbox, gearbox The main oil pressure from a pull to adjust the throttle.
4, the mechanical structure, the old section of the ATF automatic transmission oil and differential oil are separate, differential and gearbox have a main vent. In order to facilitate the repair and maintenance of gear box, automatic transmission will later differential gear oil to the oil, removed the structural design of the oil used to separate the two double-sided seal, and vent holes as a single entity (Figure 4), which prevent any damage caused by double oil seals damaged two oil mixed with gearbox failure.
5,90 late Toyota automatic transmission (such as: A341E, A541E, etc.), the electronic control system has made some improvements, mainly designed a EPC solenoid valve on the gearbox to adjust back-pressure accumulator to improve the vehicle’s shift smoothness. But it did not affect transmission of the main oil pressure, so these are still the design of a gearbox to adjust the main hydraulic throttle pull.
6,2000 years later automatic transmission (such as: U140F, U540E, etc.) are electronically controlled automatic transmission for the whole. In the electronic control system, not only designed a specialized EPC solenoid valve to control the main oil pressure, also designed one or more valves smooth shifting, better vehicle improved shift smoothness and ride comfort.
Figure 4 differential and gearbox of the main vent connected to a row Figure 5 one-way clutch gear speed A340E
Fourth, the work of elements detected correctly:
1, speed gear clutch inspection:
Toyota’s speed automatic transmission gear clutch and reverse gear in the 1,2,3-block to be involved, if I wear or erosion, in the one-way clutch slip speed gear transmission will not result in any gear, so maintenance should pay attention to check the speed of static gear hydraulic clutch is standard. Precursor for the Toyota automatic transmission, its speed gear clutch gearbox generally installed in the rear, are prone to the phenomenon of clutch drum pressure relief, maintenance should also pay attention to its dynamic hydraulic testing (when conditions on the assembly tester test.)
2, one-way clutch gear speed check:
The role of the force on the table from the device can be seen one way clutch gear speed (Figure 5) is responsible for preventing speeding planetary line in the planet carrier to turn left, if damaged skid, it is responsible for the work of the clutch to change gear by a speeding charge All the gear transmission are also, but only because the majority of speeding gear clutch friction plate 2 to 3 (only one individual friction plate), when the vehicle load increases dramatically (eg: start and emergent accelerant), occur speed gear clutch slipping slightly, if not timely replacement of one-way clutch speed gear, speed gear clutch will cause continuous erosion phenomenon. Therefore, maintenance of the Toyota automatic transmission, should pay attention to check whether the spin speed gear one-way clutch may be worn to observe the situation first, if badly worn, should be directly replaced; If you do not find significant wear and tear, plus load should also be tested and Check.
3, solenoid valve check:
Toyota electrically controlled automatic transmission generally have 3 to 5 solenoid valve, in which two of the smaller diameter shift solenoid valve, for "D" position on the four forward gears, the larger diameter is EPC and the TCC solenoid valve were responsible for regulating oil pressure and torque converter lock work. Shift solenoid valve are generally closed-off solenoid valve often, resistance is 12.5Ω about direct action can use 12V voltage test; EPC and the TCC solenoid valve is normally pulsed electromagnetic valve (Figure 6), its resistance is about to 5Ω, can not be directly tested with 12V voltage action, or it may burn solenoid valve, connected in series can be used for maintenance of a light bulb or a small resistance movement resistance, etc. were tested.