Contents Wiring diagrams Section: Transfer Case All sections

Transfer Case - Bw 4484: NVH Hummer H2 I

Transfer Case Popping Noise

CauseCorrection
DEFINITION: A faulty internal transfer case component that causes a popping noise in the transfer case. Review the Symptoms - Transfer Case and perform the necessary inspections.
Chain jumpReplace the chain and sprockets. Refer to Transfer Case Disassemble and Transfer Case Assemble . Replace the shaft bearings. Refer to Transfer Case Disassemble and Transfer Case Assemble . Inspect for damaged components caused by metal debris. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Transfer Case Popping Noise

Transfer Case Whine or Rumble Noise

CauseCorrection
DEFINITION: A faulty internal transfer case component that causes a whine noise in the transfer case. Review the Symptoms - Transfer Case and perform the necessary inspections.
Faulty bearingsInspect all of the bearings and journals. Refer to Cleaning and Inspection . Replace any faulty bearings and any components with faulty bearing journals. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Transfer Case Whine or Rumble Noise

Transfer Case Growl or Grinding Noise

CauseCorrection
DEFINITION: A faulty internal transfer case component that causes a growl or grinding noise in the transfer case while the vehicle is turning. Review the Symptoms - Transfer Case and perform the necessary inspections.
High/low planetary carrier assemblyInspect the high/low planetary carrier pinion gears for the following conditions: Chipped, bent or deformed teeth Pinion gear needle bearing worn Pinion gear thrust washers missing Seized or binding pinion gears Refer to Cleaning and Inspection . Inspect the high/low planetary carrier input gear for excessive thrust end play. Inspect the input gear teeth for excessive wear or damage. Replace the high/low planetary carrier assembly if any of the above conditions exist. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Annulus gearInspect the annulus gear for teeth damage or wear. Refer to Cleaning and Inspection . Replace the annulus gear if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Planetary differentialInspect the planetary differential pinion gears for the following conditions: Chipped, bent or deformed teeth Pinion gear bushings worn Pinion gear thrust washers missing Seized or binding pinion gears Refer to Cleaning and Inspection . Inspect the planetary differential for deformation. Refer to Cleaning and Inspection . Replace the planetary differential assembly if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Sun gearsInspect the sun gears for the following conditions: Gear tooth failure Worn or galled thrust surfaces Refer to Cleaning and Inspection . Replace the sun gears if they are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Thrust washersInspect the thrust washers for seizure to the planetary differential. Inspect the thrust washers for galling. Replace the thrust washers if they are faulty and the mating component if it is damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Planetary differential not timed properlyInspect the planetary differential for being timed properly. Refer to Transfer Case Assemble . Properly time the planetary differential gears. Refer to Transfer Case Assemble .

Transfer Case Growl or Grinding Noise

Transfer Case Clunk in 4HI Lock

CauseCorrection
DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI Lock range only. Review the Symptoms - Transfer Case and perform the necessary inspections.
Incorrect fluid level or incorrect fluidInspect the transfer case for the correct fluid level. Refer to Transfer Case Fluid Replacement . Inspect the transfer case for the correct type of fluid. Flush the transfer case and fill with the correct fluid, if required. Refer to Capacities - Approximate Fluid .
Worn high speed teeth on the range sleeveInspect for worn high speed teeth on the range sleeve. Refer to Cleaning and Inspection . Replace the range sleeve if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or missing input gear thrust washerReplace the worn or missing input gear thrust washer. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or faulty planetary differentialInspect the planetary differential for the following conditions: Loose planetary differential splines to mainshaft splines Loose or faulty pinion gears Refer to Cleaning and Inspection . Replace the planetary differential assembly if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or missing rear output shaft thrust washersInspect to ensure the thrust washers are installed. Inspect the thrust washers and mating surface for excessive wear. Replace the worn or missing thrust washer. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or damaged rear sun gearInspect the sun gear external gear teeth for excessive wear. Inspect the sun gear to rear output shaft for excessive looseness. Replace the sun gear or rear output shaft if it is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Rear output shaft bearing outer retaining ringInspect for the following conditions: Properly installed rear output shaft bearing retaining ring Excessive wear or damage to the retaining ring groove in the rear case half Refer to Cleaning and Inspection . Repair or replace the following components if found faulty: Replace the rear output shaft bearing outer retaining ring. Replace the rear case half if the retaining ring groove is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Lockup shift assembly hubInspect the lockup shift assembly hub for the following conditions: The hub internal teeth to inner lockup hub for excessive looseness caused by wear The hub engagement teeth for wear Refer to Cleaning and Inspection . Replace the lockup shift assembly if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Transfer Case Clunk in 4HI Lock

Transfer Case Clunk in 4LO Lock

CauseCorrection
DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in 4LO Lock range only. Review the Symptoms - Transfer Case and perform the necessary inspections.
High/low planetary carrier assemblyInspect for the following conditions: Excessively worn planetary gears The planetary gears loose in the planetary carrier The input gear for missing thrust washers or excessive thrust end play in the carrier Excessively worn range sleeve engagement teeth on the carrier Refer to Cleaning and Inspection . Replace the high/low planetary if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Annulus gearInspect the annulus gear to front case fit for excessive looseness. Inspect the front case for wear caused by excessive looseness. Replace the front case half if it is worn.
Range sleeveInspect the range sleeve engagement teeth for excessive wear. Inspect the range sleeve to mainshaft splines for excessive wear. Replace the range sleeve if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Transfer Case Clunk in 4LO Lock

Transfer Case Clunk during Acceleration and Deceleration

CauseCorrection
DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer case while in the 4HI mode. Review the Symptoms - Transfer Case and perform the necessary inspections.
Incorrect fluid level or incorrect fluidInspect the transfer case for the correct fluid level. Refer to Transfer Case Fluid Replacement . Inspect the transfer case for the correct type of fluid. Flush the transfer case and fill with the correct fluid, if required. Refer to Capacities - Approximate Fluid .
Excessive clearance between the slip yoke and the rear output shaftInspect for the following conditions: Worn slip yoke splines Worn rear output shaft splines Repair or replace the following components, if faulty. Replace the slip yoke, if required. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft. Replace the rear output shaft, if required. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Excessive clearance between the slip yoke and the rear bushingInspect for the following conditions: Worn rear bushing Worn slip yoke bushing journal Repair or replace the following components, if faulty. Replace the slip yoke, if required. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft. Replace the rear case half if the rear bushing is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn high speed teeth on the range sleeveInspect for the following conditions: Worn high speed teeth on the range sleeve Worn or missing input gear thrust washers Refer to Cleaning and Inspection . Repair or replace the following components, if faulty. Replace the range sleeve if it is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble . Replace the thrust washers, as required. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or faulty planetary differentialInspect the planetary differential for the following conditions: Loose planetary differential splines to the mainshaft splines Loose or faulty pinion gears Refer to Cleaning and Inspection . Replace the planetary differential assembly if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or missing rear output shaft thrust washersInspect to ensure the thrust washers are installed. Inspect the thrust washers and mating surface for excessive wear. Replace the worn or missing thrust washer. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or damaged rear sun gearInspect the sun gear external gear teeth for excessive wear. Inspect the sun gear to rear output shaft for excessive looseness. Replace the sun gear or rear output shaft if it is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Worn or damaged front sun gearInspect the sun gear external gear teeth for excessive wear. Inspect the sun gear to drive gear teeth for excessive wear. Replace the sun gear or drive gear if it is worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Rear output shaft bearing outer retaining ringInspect for the following conditions: Proper installation of the rear output shaft bearing retaining ring Excessive wear or damaged retaining ring groove in the rear case half Repair or replace the following components if found faulty: Properly install a new rear output shaft bearing outer retaining ring. Replace the rear case half if the retaining ring groove is excessively worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Transfer Case Clunk during Acceleration and Deceleration