Mazda Automatic Transaxle JA5A-EL. Manual — part 22

AUTOMATIC TRANSAXLE

K–69

K

Fourth Gear (D range)

Outline

• Shift solenoids A and B are OFF, and only C is ON in fourth gear.

• As shift valve B moves to the lower side, operation pressure of the low clutch is drained. Then, as the shift

valve C moves to the upper side, operation pressure is supplied to the 2-4 brake.

Operation

• The driving force of the input shaft is transmitted to the front planetary carrier via the high clutch causing it to

revolve the front pinion counterclockwise. However, as the load from the vehicle is applied, the front pinion tries

to rotate clockwise and the front sun gear tries to rotate counterclockwise.

• Since the front sun gear is fixed by engagement of the 2-4 brake, the front pinion tries to rotate

counterclockwise, while revolving counterclockwise because the front sun gear is fixed.

• Due to this, the driving force of the front pinion overcomes the load from the vehicle to rotate the front internal

gear counterclockwise faster than the counterclockwise rotation speed of front planetary carrier (input).

(Rotation speed of the output gear is faster than that of the input shaft.)

• The driving force transmission of the reduction gear is the same as that in first gear.

• During deceleration, engine braking is not applied for the same reason as that of first gear.

AMU0517A571

K–70

AUTOMATIC TRANSAXLE

AMU0517A572

AUTOMATIC TRANSAXLE

K–71

K

Fourth Gear (D range HOLD, S, L range)

Outline

• The operation of the front planetary gear and rear planetary gear of fourth gear in the D range HOLD, S, and L

range is the same as that of D range in the fourth gear.

• However, since the reduction timing solenoid is OFF, the reduction timing valve is switched to adjust the

reduction reducing pressure higher and engage the reduction brake, resulting in engine braking being applied.

• Line pressure is also switched to high pressure before cut back to prepare for engine braking.

AMU0517A573

K–72

AUTOMATIC TRANSAXLE

Operation

• The driving force of the input shaft is transmitted to the front planetary carrier via the high clutch causing it to

revolve the front pinion counterclockwise. However, as the load from the vehicle is applied, the front pinion tries

to rotate clockwise and the front sun gear tries to rotate counterclockwise.

• Since the front sun gear is fixed by engagement of the 2-4 brake, the front pinion tries to rotate

counterclockwise, while revolving counterclockwise because the front sun gear is fixed.

• Due to this, driving force of the front pinion overcomes the load from the vehicle to rotate the front internal gear

counterclockwise faster than the counterclockwise rotation speed of front planetary carrier (input). (Rotation

speed of the output gear is faster than that of the input shaft.)

• The driving force transmission in reduction gear is the same as that in the first gear.

• During deceleration, engine braking is not applied for the same reason as that of L range HOLD in second

gear.