Fourth Gear in ’D’ Range (Automatic gearbox - JF403E)

Fourth Gear in ’D’ Range

The high clutch is engaged and connects the input shaft and front planetary carrier, the brake band is also applied to lock the front sun gear. The forward clutch is also engaged, but it free-wheels due to the forward one-way clutch not being engaged and does not transmit power.

Power is transmitted from the input shaft to the front planetary carrier via the high clutch. When the front planetary carrier rotates in a forward direction and the front sun gear is locked by the brake band, the front internal gear is speeded up, so that forward rotation is transmitted to the output shaft. The gear ratio is 0.694:1

During over-run, a counter driving force is transmitted to the engine to obtain engine braking without assistance of the one-way clutch.

Component condition:

High clutch - Engaged

Brake band - Operative

Forward clutch - Engaged, but does not transmit the power

Power path:

Input shaft - High clutch - Front planetary carrier - Front pinion gear - Forward internal gear - Rear planetary carrier - Output shaft