Isuzu KB P190. Manual - part 1174

7B1-90     MANUAL TRANSMISSION 

Disassembly 

  1. Use a pair of snap ring pliers to remove the top gear

shaft snap ring. 

  2. Remove the top gear shaft with ball bearing. 

  3. Use a bench press and the bearing remover 5-8840-

0015-0 to remove the ball bearing. 

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 4. Remove the needle bearing and top block ring,

mainshaft snap ring. 

 5. Use a pair of snap ring pliers to remove the

mainshaft snap ring. 

  

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  6. Use a bench press and the bearing remover 5-8840-

0015-0 to remove the 3rd-4th synchronizer 
assembly as a set. 

Disassemble the synchronizer assembly. 

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Legend 

(1)

Springs 

(2)

Sleeve 

(3)

Clutch Hub 

(4)

Inserts 

 7. Remove the 3rd block ring, 3rd gear, and needle 

bearing. 

  8. Use a bench press and the bearing remover 5-8840-

0015-0 to remove the 1st gear together with the
mainshaft ball bearing, 1st gear thrust bearing, and 
the needle bearing collar. 

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MANUAL TRANSMISSION     7B1-91 

9.Disassemble the 1st inside ring, 1st outside ring, and 

1st block ring. 

10.Remove the needle bearing. 
11.Use a pair of snap ring pliers to remove the clutch 

hub snap ring. 

  

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12.Use a bench press and the bearing remover 5-8840-

0015-0 to remove the 2nd gear together with 1st-2nd 
synchronizer assembly, 2nd block ring, 2nd outside 
ring, and inside ring. 
Disassemble the synchronizer assembly. 

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Legend 

(1) Springs 

(2) Sleeve 

(3) Clutch 

Hub 

(4) Inserts 

 

 

 13. Remove the needle bearing from the mainshaft. 

 14. Remove the bearing snap ring. 

 15. Remove the front roller bearing by performing the 

following steps. 
•  Remove the ring, outer race and bearing 

assembly by using a bench press and remover 
5-8840-0015-0. 

•  Remove the inner race by using a bench press 

and remover 5-8840-0015-0. 

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 16. Remove the center roller bearing from the counter 

gear shaft. 

 

 

 

7B1-92     MANUAL TRANSMISSION 

Inspection and Repair 

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

Block Ring and Dog Teeth Clearance 

 

• Use a thickness gauge to measure the clearance

between the block ring and the dog teeth. 

  

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If the measured value exceeds the specified limit,
the block ring must be replaced. 

 

Block Ring and Dog Teeth Clearance 

Standard Limit 

1.5 mm (0.059 in) 

0.8 mm (0.031 in) 

 

 

 

MANUAL TRANSMISSION     7B1-93 

1st-2nd Synchronizer (3-CONE) 

 

• Use a thickness gauge to measure the clearance

between the block ring and the dog teeth. 

  

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If the measured value exceeds the specified limit,
the 1st-2nd synchronizer assembly must be
replaced. 

 

Block Ring and Dog Teeth Clearance 

Standard Limit 

1.5 mm (0.059 in) 

0.8 mm (0.031 in) 

Block Ring and Insert Clearance 

 

•  Use a vernier caliper or thickness gauge to measure

the clearance between the block ring and the insert.

  

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If the measured value exceeds the specified limit,
the block ring and the insert must be replaced. 

 

 

 

Block and Insert Clearance 

 Standard  Limit 

3rd-4th 

3.46 - 3.76 mm 

(0.136 - 0.148 in) 

4.0 mm 

(0.157 in) 

1st-2nd

3.86 – 4.16 mm 

(0.152 - 0.164 in) 

4.9 mm 

(0.193 in) 

Rev.5th

3.59 - 3.91 mm 

(0.141 - 0.154 in) 

4.1 mm  

(0.161 in) 

 

Clutch Hub and Insert Clearance 

 

• Use a thickness gauge to measure the clearance 

between the clutch hub and the insert. 

  

226RS038

If the measured value exceeds the specified limit, 
the clutch hub and the insert must be replaced. 

 

Clutch Hub and Insert Clearance 

 Standard  Limit 

1st-2nd

3rd-4th 

0.01 – 0.21 mm 

(0.0004 - 0.0083 in) 

0.3 mm 

(0.012 in) 

Rev-5th

0.09 – 0.31 mm 

(0.0035 - 0.0122 in) 

0.4 mm 

(0.016 in)