Drive Range, Fourth Gear (Mechanical Powerflow): Notes

WARNING: This page is about a different variant/trim than selected.

Note: The component callouts in the text refer to the component callout numbers in disassembled views. Disassembled Views (10L60)Disassembled Views (10L80)Disassembled Views (10L90)

As vehicle speed increases, input signals from the transmission speed sensors (input and output), throttle position (TP) sensor, and other vehicle sensors are sent to the transmission control module (TCM). The TCM processes this information to determine the precise moment to shift the transmission. In 4th gear, the planetary gearset continues to operate in reduction at a gear ratio of approximately 1.779:1. As vehicle speed increases, less torque multiplication is needed to move the vehicle efficiently. Therefore, it is desirable to shift the transmission to a lower gear ratio, or 5th gear.

1. Power from Torque Converter

The power flows through the turbine shaft to the input carrier (62) which is splined to the turbine shaft (568) and rotate at the same speed and direction.

2. Input Carrier Driving

The power flows to the input carrier (62) which is splined to the turbine shaft (568) and rotates at the same speed and direction. Power flow continues through the input carrier pinion gears which are driving the direct overdrive sun gear shaft (65).

3. Direct Overdrive Sun Gear Shaft Driven

The input internal gear (500) which is splined to the direct overdrive sun gear shaft (65) and rotates at the same speed and direction is driven by the input carrier (62) pinion gears.

4. 2-3-4-5-7-9-10 Clutch Assembly Applied

The 2-3-4-5-7-9-10 clutch which is part of the triple clutch housing (66) is applied and holding the input internal gear (500) which is splined to the direct overdrive sun gear shaft (65) and rotates at the same speed and direction.

5. 4-5-6-7-8-9-10 Reverse Clutch Assembly Applied

The 4-5-6-7-8-9-10 reverse clutch which is part of the triple clutch housing (66) is applied and holding the output carrier internal gear transfer shell (71) which is splined to the reaction carrier (55) and the output carrier internal gear (74), both rotate at the same speed and direction.

6. Output Carrier Internal Gear Transfer Shell

The output carrier internal gear transfer shell is held by the 4-5-6-7-8-9-10 reverse clutch which is part of the triple clutch housing (66). The output carrier internal gear transfer shell rotates at the same speed and direction as the triple clutch housing (66) and the direct overdrive sun gear (68).

7. Output Carrier Internal Gear Driving

The output carrier internal gear (74) which is splined to the output carrier internal gear transfer shell (71) is driving the output carrier (38) and rotates at the same speed and direction.

8. 1-2-3-4-6-7-8-10 Reverse Clutch Assembly Applied

The 1-2-3-4-6-7-8-10 reverse clutch which is part of the triple clutch housing (66) is applied and holding the direct overdrive carrier (67) and rotates at the same speed and direction.

9. Direct Overdrive Carrier Held

The direct overdrive carrier (67) is held by the 1-2-3-4-6-7-8-10 reverse clutch which is part of the triple clutch housing (66). The direct overdrive carrier rotates at the same speed and direction as the triple clutch housing (66) and the direct overdrive sun gear (68).

10. Direct Overdrive Sun Gear Driving

The direct overdrive sun gear (68) which is splined to the direct overdrive sun gear shaft (65) rotates at the same speed and direction as the triple clutch housing (66) and the direct overdrive carrier (67).

11. Direct Overdrive Internal Gear Driven

The direct overdrive internal gear (551) which is splined to the output sun gear (572) is driven by the direct overdrive carrier (67) at the same speed and direction.

12. Output Sun Gear Driving

The output sun gear (572) is driving the output carrier (38) pinion gears.

13. Output Carrier Driven

Powerflow continues through the output sun gear (572). Which drives the output carrier (38) pinions to achieve the 4th gear starting ratio of approximately 1.779:1.

14. Reaction Carrier Driven

The reaction carrier (55), which is splined to the output carrier internal gear transfer shell (71), rotates at the same speed and direction.

15. Low Clutch Roller Overrunning

When the throttle is released the low clutch roller (OWC) (421) will overrun, allowing the vehicle to coast, at least briefly, until the TCM determines that engine braking is required.

16. 1-2-3-4-5-6 Reverse Clutch Assembly Applied

The 1-2-3-4-5-6 reverse clutch assembly (30-35) is applied and holding the reaction internal gear (52).