Shift Mechanism

Shift Mechanism





CONSTRUCTION





FUNCTION OF CLUTCH AND BRAKE





CLUTCH AND BAND CHART
*1: Operates when overdrive control switch is set in OFF position.
*2: Oil pressure is applied to both 2nd "apply" side and 3rd "release" side of band servo piston. However, brake band does not contract because oil pressure area on the "release" side is greater than that on the "apply" side.
*3: Oil pressure is applied to 4th "apply" side in condition *2 above, and brake band contracts.
*4: A/T will not shift to 4th when overdrive control switch is set in OFF position.
*5: Operates when overdrive control switch is OFF.
O: Operates
A: Operates when throttle opening is less than 3/16, activating engine brake.
B: Operates during "progressive" acceleration.
C: Operates but does not affect power transmission.
D: Operates when throttle opening is less than 3/16, but does not affect engine brake.

POWER TRANSMISSION
P and N Positions
- P position
Similar to the N position, the clutches do not operate. The parking pawl engages with the parking gear to mechanically hold the output shaft so that the powertrain is locked.





- N position
Power from the input shaft is not transmitted to the output shaft because the clutches do not operate.








1(1) Position
- Forward clutch As overrun clutch engages, rear internal gear is locked by the operation of low and reverse brake.
- Forward one-way clutch This is different from that of D1 and 21.
- Overrun clutch
- Low and reverse brake
Engine Overrun clutch always engages, therefore engine brake can be obtained when decelerating.





D1 and 2(1) Positions
- Forward one-way clutch Rear internal gear is locked to rotate counterclockwise because of the functioning of these three clutches.
- Forward clutch
- Low one-way clutch
Overrun clutch D1 engagement conditions (Engine brake): Overdrive control switch OFF and throttle opening is less than 3/16.
21: Always engages
At D1 and 21 positions, engine brake is not activated due to free turning of low one-way clutch.





D2, 3(2), 2(2) and 1(2) Positions
- Forward clutch Rear sun gear drives rear planetary carrier and combined front internal gear. Front internal gear now rotates around front sun gear accompanying front planetary carrier. As front planetary carrier transfers the power to rear internal gear through forward clutch and forward one-way clutch, this rotation of rear internal gear increases the speed of rear planetary carrier compared with that of the 1st speed.
- Forward one-way clutch
- Brake band
Overrun clutch D2 engagement conditions: Overdrive control switch OFF and throttle opening is less than 3/16 22 and 12: Always engaged





D3 and 3(3) Positions
- High clutch Input power is transmitted to front planetary carrier through high clutch. And front planetary carrier is connected to rear internal gear by operation of forward clutch and forward one-way clutch.
- Forward clutch
- Forward one-way clutch This rear internal gear rotation and another input (the rear sun gear) accompany rear planetary carrier to turn at the same speed.
Overrun clutch D3 engagement conditions: Overdrive control switch OFF and throttle opening is less than 3/16





D4 (O/D) Position
- High clutch Input power is transmitted to front carrier through high clutch.
- Brake band This front carrier turns around the sun gear which is fixed by brake band and makes front internal gear (output) turn faster.
- Forward clutch (Does not affect power transmission)
Engine brake At D4 position, there is no one-way clutch in the power transmission line and engine brake can be obtained when decelerating.





R Position
- Reverse clutch Front planetary carrier is stationary because of the operation of low and reverse brake.
- Low and reverse brake Input power is transmitted to front sun gear through reverse clutch, which drives front internal gear in the opposite direction. Engine brake As there is no one-way clutch in the power transmission line, engine brake can be obtained when decelerating.