Reverse (Mechanical Powerflow): Notes

WARNING: This page is about a different car, the 2020 Buick Regal and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

In Reverse (R), torque from the engine is multiplied through the torque converter assembly (14), the transmission gear sets, and the front differential carrier assembly (238), thereby sending power to the vehicle's drive axles. The planetary gear sets operate in reduction and also reverse the direction of input torque. The gear ratio for Reverse gear range is 2.960: 1. When the gear selector lever is moved into the Reverse (R) gear range, the parking pawl (715) disengages from the parking gear (232) allowing the drive sprocket (234) and connected components to rotate. The manual shift detent lever (709) and manual valve (452) are also moved into the Reverse gear position in order to channel the transmission fluid.

1. Power From The Engine

Torque from the engine is transferred to the transmission through the engine flywheel which is bolted to the torque converter assembly (14).

2. Turbine Shaft Driven

As the torque converter turbine rotates, the 5-7-reverse and 6-7-8-9 clutch housing (530) and the turbine shaft (547) which is splined to the torque converter turbine, is also forced to rotate at turbine speed.

3. Input Sun Gear Driving

The input sun gear (551), which is splined to the turbine shaft (547), drives the input carrier assembly (552) pinion gears.

4. Input Carrier Assembly Driven

The input carrier assembly drives the output carrier assembly (555) pinions.

5. 5-7-Reverse Clutch Applied

The 5-7-reverse clutch plates (578-582) are applied and connect the 3-5-reverse and 6-7-8-9 clutch housing (530) to the 3-8 and 5-7-reverse clutch hub (534).

6. 1- Reverse and 1-2-3-4-5-6 Clutch Piston Applied

The 1- reverse and 1-2-3-4-5-6 clutch piston is applied and holds the overdrive carrier (546)

7. Overdrive Carrier Held

The overdrive carrier (546) is held by the 1- Reverse and 1-2-3-4-5-6 Clutch Piston housing (590).

8. 3-8 and 5-7-Reverse Clutch Hub Driving

With the overdrive carrier (546) held by the 1- Reverse and 1-2-3-4-5-6 Clutch Piston housing (590), the 3-8 and 5-7-reverse clutch hub (534) drives the overdrive carrier assembly pinion gears.

9. Output Carrier Assembly Drive

The overdrive carrier (546) pinion gears are in mesh with, and drive, the internal gear (output carrier assembly) (555) in the direction opposite of torque converter rotation to achieve reversal of direction.

10. Output Carrier Transfer Drive Gear Hub Driven

The output carrier transfer drive gear hub (502) is splined to, and driven by, the output carrier assembly (555).

11. Drive Sprocket Driving

The drive sprocket (234), splined to and driven by the output carrier transfer drive gear hub (502), drives the drive link (233) which drives the driven sprocket (241).

12. Driven Sprocket Driven

The driven sprocket (241), driven by the drive link (233), is splined to the front differential carrier sun gear (240).

13. Front Differential Carrier Sun Gear Driving

The front differential carrier sun gear (240), is in mesh with, and drives, the front differential carrier (238), thus transferring power to the front differential carrier and to the drive axles.