Isuzu KB P190. Manual - part 1070

CONSTRUCTION AND FUNCTION  7A1-41 

1st Gear in D, 3, 2 Position 
The driving force from the input shaft is transmitted to the rear sun gear and reverse & high clutch drum.  As 
the low clutch is engaged, the movement of the rear internal gear is restricted.  Since the low one-way clutch 
acts at the same time, counterclockwise rotations of the rear internal gear are locked.  As a result, the driving 
force transmitted to the rear sun gear rotates the rear planetary carrier clockwise, then the rotation speed is 
decreased and multiple force is transmitted to the output shaft. 
When decelerating, the rotating speed of the rear planetary carrier (rear pinion gear) is higher than that of the 
rear sun gear and the rear internal gear attempts to rotate clockwise.  At this time, the low one-way clutch 
does not act but races, and therefore the rear internal gear rotates clockwise.  The reverse torque from the 
driving shaft is not transmitted to the engine side and the engine brake does not act. 
 

 

 
 

 

 

 

 

 
 
 

7A1-42  CONSTRUCTION AND FUNCTION 

1st Gear in L Position 
The basic mechanism is the same as in the D, 3, and 2 positions.  To apply the engine brake, the low & 
reverse brake is engaged to restrict the movement of the low one-way clutch. 
When decelerating, as the rear internal gear is fixed, reverse torque from the drive shaft is transmitted to the 
engine side so that the engine brake is applied. 
 

 

 
 

 

 

 

 

CONSTRUCTION AND FUNCTION  7A1-43 

2nd Gear in D, 3, 2 Position 
The driving force from the input shaft is transmitted to the rear sun gear and reverse & high clutch drum.  As 
in the case of the 1st gear, the low clutch is engaged and the movement of the rear internal gear is restricted.  
Since the 2-4 brake is engaged, the front sun gear is fixed.  As a result, movement of the rear internal gear is 
restricted, and the driving force transmitted to the rear sun gear rotates the rear planetary carrier clockwise.  
The rotating speed of the rear planetary carrier is higher than in 1st gear as the rear internal gear rotates. 
When decelerating, the engine brake is applied. 
 

 

 
 

 

 

 

 

 

7A1-44  CONSTRUCTION AND FUNCTION 

3rd Gear in D, 3 Position 
The driving force from the input shaft is transmitted to the rear sun gear and reverse & high clutch drum.  As 
in the case of the 1st gear and 2nd gear, the low clutch is engaged and the movement of the rear internal 
gear is restricted.  Since the high clutch is engaged, the driving force from the input shaft is directly 
transmitted to the rear internal gear.  As a result, the rpm of the rear sun gear and the rear internal gear 
becomes the same as that of the input shaft, so that the rear pinion gear rotates not independently but 
together with the rear sun gear and rear internal gear. 
When decelerating, the engine brake is applied.