Honda Civic. Manual — part 170

reverse gear engage with the countershaft.

Gears on the secondary shaft:

1st gear is engaged/disengaged with the secondary shaft by the 1st clutch.

2nd gear is engaged/disengaged with the secondary shaft by the 2nd clutch.

4th gear is engages/disengages with the secondary shaft by the 4th clutch.

Idler gear is splined with the secondary shaft, and rotates with the secondary
shaft.

The idler gear on the idler gear shaft transmits power between the mainshaft and the
secondary shaft.

The reverse idler gear transmits power from the mainshaft reverse gear to the
countershaft reverse gear, and change rotational direction of the countershaft to
reverse.

Power Flow

P Position

Hydraulic pressure is not applied to the clutches. Power is not transmitted to the
countershaft. The countershaft is locked by the park pawl interlocking the park
gear.

N Position

Engine power transmitted from the torque converter drives the mainshaft idler gear,
the idler gear shaft idler gear, and the secondary shaft idler gear, but hydraulic
pressure is not applied to the clutches. Power is not transmitted to the countershaft.
In this position, the position of the reverse selector differs according to whether the
shift lever shifted from D or R:

When shifted from D, the reverse selector engages with the countershaft 4th-
5th gear and the reverse selector hub, and the 4th-5th gear engages with the
countershaft.

When shifted from R, the reverse selector engages with the countershaft
reverse gear and the reverse selector hub, and the reverse gear engages with the

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)

countershaft.

Fig. 18: Automatic Transmission - Power Flow Diagram
Courtesy of AMERICAN HONDA MOTOR CO., INC.

D, D3 Position

In D and D3, the optimum gear is automatically selected from 1st, 2nd, 3rd, and 5th
gears in D; 1st, 2nd, and 3rd gears in D3 according to conditions such as the
balance between the throttle opening (engine loading) and the vehicle speed.

In 1st Gear and 1 Position

Hydraulic pressure is applied to the 1st clutch, then the 1st clutch engages the
secondary shaft 1st gear with the secondary shaft.

The mainshaft idler gear drives the secondary shaft via the idler gear shaft idler

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)

gear and the secondary shaft idler gear.

The secondary shaft 1st gear drives the countershaft 1st gear and the
countershaft.

Power is transmitted to the final drive gear, which in turn drives the final
driven gear.

Fig. 19: Automatic Transmission - Power Flow Diagram - 1st Gear And 1
Position
Courtesy of AMERICAN HONDA MOTOR CO., INC.

In 2nd Gear and 2 Position

Hydraulic pressure is applied to the 2nd clutch, then the 2nd clutch engages the
secondary shaft 2nd gear with the secondary shaft.

The mainshaft idler gear drives the secondary shaft via the idler gear shaft idler

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)

gear and the secondary shaft idler gear.

The secondary shaft 2nd gear drives the countershaft 2nd gear and the
countershaft.

Power is transmitted to the final drive gear, which in turn drives the final
driven gear.

Fig. 20: Automatic Transmission - Power Flow Diagram - 2nd Gear And 2
Position
Courtesy of AMERICAN HONDA MOTOR CO., INC.

In 3rd Gear

Hydraulic pressure is applied to the 3rd clutch, then the 3rd clutch engages the
mainshaft 3rd gear with the mainshaft.

The mainshaft 3rd gear drives the countershaft 3rd gear and the countershaft.

2008 Honda Civic LX

2006-08 TRANSMISSION Automatic Transmission - Civic (Except Hybrid)