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 (8) for the following conditions:

• | Spun bearing

• | Cracks

5. Inspect the input shaft bearing bore (5) for the following conditions:

• | Spun bearing

• | Cracks

6. Replace the front case half if any of the above is found.
7. Inspect the sealing surfaces (1) for damage.
8. Repair small scratches or nicks with a soft stone.
9. Inspect the front case to transmission case mounting surface for damage.
10. Inspect the case threaded bolt holes (2) for damage.
11. Repair any damaged threads.
12. Inspect the transmission to transfer case studs (4) for damage.
13. Replace any damaged studs. Refer to Transfer Case Assemble .
14. Inspect the retaining ring (3) of the annulus gear to ensure it is properly seated.
15. Inspect the annulus gear (6) for the following conditions:

• | Damage or wear

• | Chipped gear teeth

• | Debris embedded in the root of the teeth

16. Replace the front case half if the annulus gear is damaged.
17. Inspect the control actuator lever shaft bearing and seal (7) for the following conditions:

• | Roughness

• | Pitted rollers

• | Seal torn or damaged

18. Replace the control actuator lever shaft bearing if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
19. Inspect the location pins for being loose or missing.
20. Repair or replace any damaged location pins.
21. Inspect the front output shaft front bearing and the input shaft bearing for the following conditions:

• | Roughness

• | Brinelling

• | Pitting

22. Replace the bearings 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 (1) 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 oil pump wear sleeve (5) for wear, being loose, or damage.
10. Replace the oil pump wear sleeve if faulty.
11. Inspect the front output shaft rear bearing (4) for the following conditions:

• | Roughness

• | Brinelling

• | Pitting

12. Replace the front output shaft rear bearing if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble .
13. Inspect the rear output shaft bearing for the following conditions:

• | Roughness

• | Brinelling

• | Pitting

14. Inspect for a spun bearing bore for the rear output shaft rear bearing.
15. Replace the case if a bearing has spun.
16. Inspect the retaining ring (2) for the rear output shaft rear bearing for being bent or twisted.
17. Replace a faulty retaining ring.
18. Inspect the rear output shaft bushing (3) for scoring or wear.
19. Replace a faulty rear output shaft bushing. Refer to Transfer Case Disassemble and Transfer Case Assemble .

### Oil Pump

1. Remove the oil pump suction pipe and the oil pump suction hose from the oil pump screen.
2. Clean the pipe, 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 the oil pump gears turning without binding.
7. Replace the oil pump if there is any binding. Do NOT disassemble the oil pump. The pump is serviced as an assembly.

### Rear Output Shaft

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

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

3. Inspect the input gear pilot bearing surface (1) and the drive gear sleeve journal surface (4) for the following conditions:

• | Scoring

• | Pitting

• | Brinelling

• | Excessive wear

4. Inspect the rear output shaft splines (3) for damage or excessive wear. Witness marks at the location of the gears is normal.
5. Replace the rear output shaft if any of the above conditions are found.

### High/Low Planetary Carrier

1. Clean the high/low planetary carrier in cleaning solvent. Do not disassemble the planetary carrier.
2. Air dry, and ensure all cleaning solvent is removed from the bearings in the planetary gears (3). Do not spin the planetary gears with compressed air.
3. Inspect the planetary gears for chipped teeth.
4. Inspect the planetary gears for debris embedded in the root of the teeth.
5. Inspect for a washer (4) being on each side of the planetary gears.
6. Inspect the low range teeth (1) for damage or excessive wear.
7. Inspect the thrust washer surface (2) for scoring or excessive wear.
8. Replace the high/low planetary carrier if any of the above conditions are found.
9. Inspect the input gear thrust washers for excessive wear or scoring.
10. Replace the thrust washers if they are faulty.

### Drive Chain and Sprockets

1. Clean the drive chain (1), drive sprocket (3), and driven sprocket (2) in cleaning solvent and air dry.
2. Inspect the drive chain (1) for the following conditions:

• | Loose link pins

• | Binding or stiff links

• | Debris embedded in the links

• | Worn teeth surfaces

3. Replace the chain if any of the above conditions are found.
4. Inspect the driven sprocket (2) and the drive sprocket (3) for the following conditions:

• | Chipped teeth

• | Excessive worn gear surfaces, slight wear marks are normal

• | Debris embedded in the root of the teeth

5. Replace the sprocket if any of the above conditions are found. The chain and sprockets may be replaced separately.
6. Inspect the drive sprocket sleeve journal surface for the following conditions:

• | Gouging

• | Roughness

• | Excessive wear

7. Replace the sprocket sleeve if faulty.

### Front Output Shaft

1. Clean the front output shaft in cleaning solvent and air dry.
2. Inspect the front output shaft rear bearing race (1) for the following conditions:

• | Scoring

• | Pitting

• | Brinelling

• | Excessive wear

3. Inspect the front output shaft splines (2) for damage.
4. Replace the front output shaft if any of the above conditions are found.

### Input Gear

1. Clean the input gear, with pilot bearing, in cleaning solvent.
2. Air dry and ensure all solvent is removed from the pilot bearing.
3. Inspect the pilot bearing (1) for the following conditions:

• | Pitted

• | Wear

• | Corrosion

4. Replace the input gear pilot bearing if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble .
5. Inspect the input gear engagement teeth (2) for chips.
6. Inspect the input gear for broken or damaged planetary teeth (3).
7. Inspect the input gear for debris embedded in the root of the teeth.
8. Inspect the input gear seal surface (4) for pitting or excessive wear.
9. Replace the input gear if any of the above conditions are found.

### Shift System Components

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

• | The high/low shift fork (1)

• | The range sleeve (2)

• | The two/four wheel drive mode shift fork (3)

• | The shift fork shaft (4)

• | The control actuator lever shaft (5)

• | The synchronizer gear (6)

• | The synchronizer assembly (7)

2. Inspect the shift fork shaft for straightness (4).
3. Replace the shift fork shaft if it is not straight.
4. Inspect the synchronizer gear (6) for chipped or worn engagement teeth.
5. Replace the gear if faulty.
6. Inspect the pads (1) on the high/low shift fork for wear.
7. Inspect the pin (2) on the shift fork for wear.
8. Replace the shift fork if the pin is worn or the pads are worn.

Important: Only disassemble the shift fork assembly if replacing a faulty component.

9. Inspect the following components of the shift fork assembly for wear or damage:

• | The spring (2)

• | The washers (3)

• | The bracket (4)

• | The shift fork (1)

10. Inspect the two/four wheel drive mode shift fork roller (1) for the following conditions:

• | Wear

• | Rotates easily

11. Inspect the shift fork for worn wear pads (3).
12. Inspect the shift fork bearing (2) for being faulty.
13. Replace the shift fork if the above conditions are found.
14. Inspect the range sleeve for chipped or excessive worn teeth (1).
15. Inspect the shift fork collar (2) on the range sleeve for wear.
16. Inspect the inner splines (3) of the range sleeve for excessive looseness on the rear output shaft.
17. Replace the range sleeve if the above conditions are found.
18. Inspect the high/low shift fork roller slot (2) on the control actuator lever shaft for wear or roughness.
19. Inspect the bearing (1) and the seal surface on the control actuator lever shaft for the following conditions:

• | Pitted

• | Wear

• | Corrosion

20. Inspect the two/four wheel drive mode shift fork cam lobes (3) on the control actuator lever shaft for wear or roughness.
21. Inspect the detent plunger cam lobes (4) for wear or roughness.
22. Replace the control actuator lever shaft if any of the above conditions are found.
23. Inspect the inner synchronizer ring (1) for wear and roughness.
24. Inspect the middle synchronizer ring (2) friction material for wear or damage.
25. Inspect the outer synchronizer ring (3) for wear.
26. Inspect the synchronizer sleeve (4) for the following conditions:

• | Wear on the engagement teeth

• | Wear in the insert notches

27. Inspect the synchronizer hub (6) for the following conditions:

• | Loose fit on the rear output shaft

• | Broken or damaged insert springs (5 and 8)

• | Worn inserts (7)

28. Replace the synchronizer assembly if any of the above parts are faulty.