Geartrain

DESCRIPTION
Power is transmitted from the torque converter to the planetary gearsets through the input shaft.

By holding and driving certain numbers of the gearsets, four forward ratios and one reverse ratio are obtained and transmitted to the output shaft and differential.

The ratios from the planetary gearsets are:
2.474:1 in 1st(Low)
1.474:1 in 2nd (Intermediate)
1.000:1 in 3rd (Drive)
.75:1 in 4th (Overdrive)
2.1:1 in Reverse





OPERATION
Planetary Gearset-Overdrive
The planetary gear overdrive carrier is driven by the input shaft. The planetary gearset overdrive carrier drives the center shaft via the overdrive one-way clutch in 1st, 2nd and 3rd gears.

In overdrive, the overdrive sun gear is held, causing the pinion gear to rotate around the overdrive sun gear. The pinion gears in turn drive the overdrive ring gear resulting in an overdrive output ratio of 0.75:1.

The overdrive planetary gearset is also internally splined to the coast clutch for engine braking.





Planetary Gearset-Forward
The forward planetary gearset is splined to the output shaft.

The forward planetary gearset is driven by the forward ring gear when the forward clutch is applied. The forward planetary gearset pinions drive the forward sun gear. The forward sun gear is splined to the input shell.

Input Shaft
The input shaft is supported by two bushings in the stator support. End positioning of the input shaft is controlled by the splines in the converter turbine and the overdrive planetary carrier.

Output Shaft
The output shaft is supported by two bushings in the case and by the slip yoke bushing in the extension housing. End positioning is controlled by the parking pawl gear and snap ring or shoulder and by the reverse ring gear hub and snap ring.





Planetary Gearset-Low/Reverse
The low/reverse planetary gearset is connected to the low/reverse brake drum by lugs from the low/reverse brake drum to the lugs of the low/reverse planetary gearset.

The low/reverse planetary gearset is driven by the forward sun gear which is splined to the input shell.

The splines of the forward sun gear drive the pinions in the low/reverse planetary gearset. The pinions of the low/reverse planetary gearset drive the output shaft ring gear and output shaft hub which is splined to the output shaft.

The low/reverse planetary gearset is held via the low one-way clutch in the low/reverse brake drum assembly, when the low/reverse band is applied.