The planetary gearset is a Ravigneaux type with primary and secondary sun gears, primary and secondary planet pinions, and one ring gear.
The ring gear is attached to the output shaft and the planet carrier is mounted in the transmission case on a one-way clutch which locates in a central support, held in position by dowel bolts.
Both sets of pinions are mounted in the planet carrier so that they mesh together in pairs and the longer outer secondary pinions mesh with the ring gear at their outer edge.
At their inner edge they mesh with the secondary sun gear, while the smaller primary pinions mesh with the smaller primary sun gear.
The planet pinions transmit the drive from the sun gears to the ring gear.
In all forward ratios, drive is transmitted through the primary sun gear while in reverse it is transmitted through the secondary sun gear.
Control of the planetary gearset is provided by the operation of two multi-plate clutches, the one-way clutch and two brake bands.
The outer plates of the front clutch are splined to the input shaft from the converter turbine while the inner plates are splined to the primary sun gear shaft.
The inner plates of the rear clutch are splined to the front clutch drum and therefore to the converter turbine, and the outer plates connect to the secondary sun gear shaft.
The front band wraps around the outside of the rear clutch drum and the rear band is on the outside of the planet carrier so that it will hold the planet carrier stationary when it is applied.
When the rear band is in the release position, the one-way clutch allows the planet carrier to rotate in a forward direction but not in a reverse direction.
