For 1990-2009 cars

### Front Case Half

1. Clean the front case half in cleaning solvent and air dry.

Notice: Refer to Machined Surface Damage Notice in the Preface section.

2. Remove the sealer from the case sealing surfaces.
3. Inspect the case for being broken or cracked.
4. Inspect the front output shaft front bearing bore (a) for the following conditions:

• | A spun bearing

• | Cracks

5. Inspect the planetary carrier bearing bore (c) for the following conditions:

• | A spun bearing

• | Cracks

6. Inspect the case annulus gear notches (b) for wear.
7. Replace the front case half if any of the above conditions are found.
8. Inspect the sealing surfaces for damage.
9. Repair small scratches or nicks with a soft stone.
10. Inspect the front case to transmission case mounting surface for damage.
11. Inspect the case threaded bolt holes for damage.
12. Repair any damaged threads.
13. Inspect the location pins (21) for being loose or missing.
14. Repair or replace any damaged location pins.
15. Inspect the breather pipe and vent hose pipes (5 and 7) for damage or leaking.
16. Replace the pipes if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
17. Inspect the control actuator shaft bushing (206) for excessive wear.
18. Replace the control actuator shaft bushing if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
19. Inspect the front output shaft front bearing for the following conditions:

• | Roughness

• | Brinelling

• | Pitting

20. Replace the bearing if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble .

### Rear Case Half

1. Clean the rear case half in cleaning solvent and air dry.

Notice: Refer to Machined Surface Damage Notice in the Preface section.

2. Remove the sealer from the case sealing surfaces.
3. Inspect the case for being broken or cracked.
4. Replace the case if it is broken or cracked.
5. Inspect the sealing surfaces for damage.
6. Repair small scratches or nicks with a soft stone.
7. Inspect the case threaded bolt holes for damage.
8. Repair any damaged threads.
9. Inspect the front output shaft rear bearing bore (a) for the following conditions:

• | Spun bearing

• | Cracks

10. Inspect the rear output shaft rear bearing bore (c) for the following conditions:

• | Spun bearing

• | Cracks

11. Replace the case if the bearing bores are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
12. Inspect the rear output shaft bushing (2) for scoring or wear.
13. Replace the bushing if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
14. Inspect the control actuator shaft bore (b) for the following conditions:

• | Out of round

• | Excessive wear

15. Replace the case if the control actuator shaft bore is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
16. Inspect the shift shaft plugs (24) for being loose or leaking.
17. Replace the shift shaft plugs if leaking. Refer to Transfer Case Disassemble and Transfer Case Assemble .

### Oil Pump

1. Remove the oil pump suction hose from the oil pump screen.
2. Clean the hose and screen in cleaning solvent and air dry.
3. If the screen is embedded with debris, replace the screen.
4. Inspect the hose for cracking or tears.
5. Replace the hose if it is faulty.
6. Inspect the oil pump for free movement.
7. Inspect for wear on the oil pump drive teeth.
8. If there is binding or worn teeth, replace the oil pump. Do not disassemble the oil pump. The oil pump is serviced as a unit.

### High/Low Range Components

1. Clean the annulus gear in cleaning solvent and air dry.
2. Inspect the annulus gear teeth for the following conditions:

• | Damage or excessive wear

• | Chipped

• | Debris embedded in the root of the teeth

3. Replace the annulus gear if it is faulty.

1. Clean the high/low range shift sleeve in cleaning solvent and air dry.
2. Inspect the high/low range shift sleeve for the following conditions:

• | Excessive wear or roughness on the shift fork pad surface (c)

• | Damaged, chipped or excessively worn engagement teeth (b)

• | Excessively loose or gouged rear output shaft splines (a)

3. Replace the high/low range shift sleeve if any of the above conditions are found.

### High/Low Planetary Carrier Assembly

1. Clean the high/low planetary carrier (100) and the planetary low gear (102) in cleaning solvent. Do not disassemble the planetary carrier.
2. Air dry and ensure all cleaning solvent is removed from the bearings in the pinion gears (108). Do not spin the pinion gears with compressed air.
3. Inspect the pinion gears for chipped teeth.
4. Inspect the pinion gears for debris embedded in the root of the teeth.
5. Inspect the pinion gears for excessive side movement from worn bearings or shafts.
6. Inspect the low range teeth (c) on the planetary low gear (102) for damage or excessive wear.
7. Inspect the planetary low gear and planetary carrier teeth (b) for excessive wear.
8. Inspect the thrust washer surface (a) for scoring or excessive wear.
9. Replace the high/low planetary carrier if any of the above conditions are found. The planetary low gear is serviced only with the planetary carrier assembly.
10. Inspect the planetary carrier bearing (114), the input shaft bearing (113) and the thrust bearing (106) for the following conditions:

• | Scoring

• | Pitting

• | Brinelling

• | Excessive wear

11. Replace faulty bearings. Refer to Transfer Case Disassemble and Transfer Case Assemble .

### Drive Chain and Sprockets

1. Clean the drive chain (120), the drive sprocket (123) and the front output shaft (127) in cleaning solvent and air dry.
2. Inspect the drive chain (120) for the following conditions:

• | Loose link pins

• | Binding or stiff links

• | Debris embedded in the links

• | Worn teeth surfaces

• | Stretched chain - interference marks on the case half

3. Replace the chain if any of the above conditions are found.
4. Inspect the driven sprocket on the front output shaft (127) and the drive sprocket (123) for the following conditions:

• | Chipped or cracked teeth

• | Excessively worn gear surfaces

• | Slight wear marks are normal.

• | Debris embedded in the root of the teeth

5. Inspect the drive sprocket (123) for the following conditions:

• | 2/4 Synchronizer engagement teeth for chipping

• | 2/4 Synchronizer engagement teeth for excessive wear

6. Inspect the drive sprocket bushing for the following conditions:

• | Excessive wear

• | Scoring

7. Inspect the rear bearing journal on the front output shaft for the following conditions:

• | Scoring

• | Pitting

• | Brinelling

• | Excessive wear

8. Inspect the threads on the front output shaft for damage.
9. Inspect the splines on the front output shaft for wear, caused by a loose flange yoke.
10. Replace the sprockets if any of the above conditions are found. The chain and sprockets may be replaced separately.

### Rear Output Shaft

1. Clean the rear output shaft in cleaning solvent.
2. Clean the rear output shaft oil galleries and air dry.

Important: Do not attempt to smooth any roughness in the bearing journals.

3. Inspect the bearing journals on the rear output shaft for the following conditions:

• | The front support bearing (d)

• | The drive gear bushing (b)

- | Scoring

- | Pitting

- | Brinelling

- | Excessive wear

4. Inspect the rear output shaft high/low range splines (c) for damage or excessive wear. Witness marks at the location of the gear are normal.
5. Inspect the rear output shaft splines (a) for wear or damage.
6. Inspect the rear output shaft bearing area (e) for a spun bearing.
7. Replace the rear output shaft if any of the above conditions are found.

### Shift System Components

#### Tools Required

J 22738-B Valve Spring Tester

1. Clean the following shift system components in cleaning solvent and air dry:

• | The 2/4 synchronizer sleeve (224)

• | The 2/4 shift fork (243)

• | The control actuator shaft (261)

• | The high/low shift fork (258)

• | The control actuator cam (262)

• | The 2/4 synchronizer inserts (226) and springs (225)

• | The 2/4 synchronizer hub (227)

• | The 2/4 synchronizer rings (223, 222 and 221)

2. Inspect the control actuator cam (262) surfaces for the following conditions:

• | Roughness

• | Grooved

• | Excessive wear

3. Replace the control actuator cam if faulty.
4. Inspect the control actuator shaft (261) for the following conditions:

• | Wear at the seal surface

• | Actuator assembly engagement teeth stripped or excessively worn

5. Replace the control actuator shaft if faulty.
6. Inspect the 2/4 synchronizer blocking ring (223) for chipped or worn engagement teeth.
7. Install the 2/4 synchronizer rings on the drive gear.
8. Using a feeler gage between the blocking ring teeth and the drive gear selector teeth, measure the synchronizer wear. Press down evenly on the rings while measuring.

Specification

• | Standard clearance: 1.5 mm (0.059 in)

• | Minimum clearance: 0.8 mm (0.031 in)

9. Measure the slots for the inserts, in the blocking ring (223), for wear.

Specification
Standard dimension: 9.5-9.7 mm (0.374-0.382 in)

10. Replace the 2/4 synchronizer rings if they are faulty.
11. Using a vernier caliper, measure the clearance between the blocking ring and the insert.
12. If the measured value exceeds the specified limit, the blocking ring and the insert must be replaced.

Specification

• | Standard blocking ring and insert clearance: 3.86-4.14 mm (0.152-0.163 in)

• | Limit blocking ring and insert clearance: 4.9 mm (0.193 in)

13. Inspect the 2/4 synchronizer hub for the following conditions:

• | Splines (a) press fit to the rear output shaft

• | Steps worn in the sleeve teeth (b)

14. Install the inserts in the hub slots.
15. Using a feeler gage, measure for wear.

Specification

• | Standard clearance: 0.01-0.19 mm (0.0004-0.0075 in)

• | Maximum clearance: 0.3 mm (0.012 in)

16. Inspect the 2/4 synchronizer sleeve for the following conditions:

• | Chipped or worn blocking ring teeth

• | Loose fit to the synchronizer hub caused by excessive wear

• | Shift fork collar surfaces for damage

17. Inspect the 2/4 synchronizer inserts for excessive wear.
18. Replace the 2/4 synchronizer assembly if any of the above conditions are found.
19. Inspect the 2/4 shift shaft for excessive wear at the detent notches.
20. Inspect the 2/4 shift fork for excessive wear at the synchronizer sleeve surfaces.
21. Inspect the 2/4 shift fork for cracks or being bent.
22. Inspect the 2/4 shift fork shaft bore for excessive wear.
23. Replace any faulty or damaged components. Refer to Transfer Case Disassemble and Transfer Case Assemble .
24. Inspect the high/low shift shaft for excessive wear at the detent notches.
25. Inspect the high/low shift block and collars for wear.
26. Replace any of the above components if they are found faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
27. Measure the sleeve pads on both shift forks for wear.

Specification

• | 2/4 wheel drive shift fork standard thickness: 9.60-9.85 mm (0.378-0.388 in)

• | 2/4 wheel drive shift fork minimum thickness: 9.0 mm (0.354 in)

• | High/Low shift fork standard thickness: 7.60-7.85 mm (0.299-0.309 in)

• | High/Low shift fork minimum thickness: 7.0 mm (0.276 in)

28. If the measured value is less than the minimum thickness, replace the shift fork. Refer to Transfer Case Disassemble and Transfer Case Assemble .
29. Inspect the detent springs for distortion or cracks.
30. Measure the detent spring free length.

Specification

• | Standard length: 23.4 mm (0.92 in)

• | Minimum length: 23.1 mm (0.91 in)

31. Measure the inner range shift detent spring free length.

Specification

• | Standard length: 26.6 mm (1.05 in)

• | Minimum length: 25.6 mm (1.01 in)

32. Use J 22738-B or equivalent to measure the detent spring tension.

Specification

• | Compressed height: 18.7 mm (0.736 in)

• | Standard tension: 7.5-8.5 kg (16.5-18.7 lb)

33. Use J 22738-B or equivalent to measure the inner range shift detent spring tension.

Specification

• | Compressed height: 18.7 mm (0.736 in)

• | Standard tension: 3.3-4.3 kg (7.3-9.5 lb)

34. Replace the detent springs if found faulty.