Isuzu KB P190. Manual - part 1157

7B1-22     MANUAL TRANSMISSION 

Inspection and Repair 

Make the necessary adjustments and part replacements
if excessive wear or damage is discovered during
inspection. 

Shift Arm Thickness 

 

• Use a micrometer to measure the shift arm

thickness. 

If the measured value is less than the specified limit,
the shift arm must be replaced. 

 

Shift Arm Thickness 

 Standard  Limit 

1st-2nd 

9.60 - 9.85 mm 

(0.378 - 0.388 in) 

3rd-4th 

Rev.5th 

9.60 - 9.80 mm 

(0.378 - 0.386 in) 

9.0 mm 

(0.354 in) 

 

 

 

230RS006

Detent Spring Free Length 

 

•  Use a vernier caliper to measure the detent spring

free length. 

If the measured value is less than the specified limit,
the detent spring must be replaced. 

 

Detent Spring Free Length 

Standard Limit 

26.8 mm (1.06 in) 

26.2 mm (1.03 in) 

 

 

SOUTH AFRICA 5th-Rev Only 

Detent Spring Free Length 

 Standard  Limit 

Outer 

27.6 mm (1.09 in) 

27.0 mm (1.06 in)

Inner 

26.6 mm (1.05 in) 

26.0 mm (1.02 in)

 

 

 

220RS012

Detent Spring Tension 

 

• Use a spring tester to measure the detent spring 

tension. 

If the measured value is less than the specified limit, 
the detent spring must be replaced. 

 

Detent Spring Tension 

Compressed height 

Standard 

20 mm (0.787 in) 

87.2 - 97.1 N 

(19.6 - 21.8 lb) 

 

 

220RS013

 

SOUTH AFRICA 5th-RV Only 

Detent Spring Free Length 

 Compressed Standard 

Outer 

20 mm (0.787 in) 

93.5 – 103.3 N 

 (21.0 – 23.3 lb) 

Inner 

20 mm (0.787 in) 

26.4 – 36.3 N 

 (5.9 – 8.2 lb) 

MANUAL TRANSMISSION     7B1-23 

Reassembly 

  1. Install the rev-5th shift arm and reverse inhibitor and 

the rev-5th shift rod. 
•  Apply oil to the reverse inhibitor inner surface. 
•  Install the shift rod in the intermediate plate. 
•  Hold a round bar against the shift rod end lower

face to protect it against damage. 

•  Install a new spring pin. 

Never reinstall the used spring pin. 

•  Install the interlock pin in the intermediate plate.

Do not allow the interlock pin to fall from the
intermediate plate. 

  2. Install the 1st-2nd shift arm and 3rd-4th shift arm to

the intermediate plate and gear assembly. 

  3. Install the 3rd-4th shift rod and 1st-2nd shift rod. 

•  Install the interlock pin in the intermediate plate

and gear assembly. 

•  Install the 3rd-4th shift rod in the intermediate

plate. 

Do not allow the interlock pin to fall from the
intermediate plate. 

•  Install the interlock pin and then 1st-2nd shift rod 

in the intermediate plate. 

Do not allow the interlock pin to fall from the
intermediate plate. 

•  Hold a round bar against the shift rod end lower

face to protect it against damage. 

•  Install a new spring pin. 

Never reinstall the used spring pin. 

 

 

230RS007

 

 

  4. Install the spring. 

  5. Put the detent balls in the intermediate plate holes.

•  Apply oil to the detent balls. 

  6. Install the detent springs and detent spring plate and 

gasket. 

NOTE: For South Africa model, it has double detent 
spring for Rev-5th shift rod. 

•  Install a new gasket and the detent spring plate.
•  Tighten the detent spring plate bolts to the 

specified torque. 

Torque: 25 N

⋅⋅⋅⋅m (2.5 kgf⋅⋅⋅⋅m/18 lb⋅⋅⋅⋅ft) 

 

 

 

220RS030

 

Legend 

(1)

Warped 

 
 

 

7B1-24     MANUAL TRANSMISSION 

Reverse Gear and 5th Gear 

Disassembled View 

 

226R300027 

 

Legend 

(1)  Bearing Snap Ring 

(11) Reverse Idler Gear Assembly 

(2)  Ball Bearing 

(12) Idle Shaft Pin 

(3)  Bearing Snap Ring 

(13) Thrust Washer 

(4)  Speedometer Drive Gear 

(14) Reverse Idler Gear 

(5)  Clip 

(15) Reverse Idler Shaft 

(6)  Retainer Snap Ring 

(16) Bearing Snap Ring 

(7) Retainer 

(17) Ball 

Bearing 

(8)  Thrust Plate 

(18) Counter 5th Gear 

(9)  Thrust Washer and Lock Ball 

(19) Counter Reverse Gear 

(10)  Reverse Idler Gear Snap Ring 

(20) 5th Gear 

MANUAL TRANSMISSION     7B1-25 

(21)  5th Block Ring 

(26) Reverse Gear 

(22)  Needle Bearing 

(27) Needle Baring 

(23)  Mainshaft Nut 

(28) Bearing Plate and Screw 

(24)  Rev-5th Synchronizer Assembly 

(29) Bearing Snap Ring 

(25)  Reverse Block Ring 

(30) Intermediate Plate