Cause | Correction | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Inspect for the proper transaxle and gear oil levels prior to performing system diagnosis. Refer to Transfer Case Fluid Replacement . | |||||||||
Water or contamination within the transmission oil Water or contamination within the transmission fluid, causing excessive torque converter clutch slip rate, may create a "grind, growl, or moan" in the rear differential or torque tube under light or steady load conditions. | Replace the transmission fluid and flush the transfer case of the contaminated fluid. Refer to Transfer Case Transmission Fiber Material Cleaning . | ||||||||
Loose propeller shaft mounting bolts | Tighten the bolts as required. Refer to Propeller Shaft Replacement in Propeller Shaft. | ||||||||
Worn propeller shaft constant velocity joints | Replace propeller shaft assembly. Refer to Propeller Shaft Replacement in Propeller Shaft. | ||||||||
Worn axle shaft constant velocity joints | Replace the constant velocity joints as required. | ||||||||
Loose rear axle torque tube bracket or a worn bracket bushing | Tighten the bracket bolts or replace the bracket as required. | ||||||||
Worn bearing in the rear differential torque tube assembly | Replace the torque tube assembly | ||||||||
Torque tube dampener loose or missing A "moan" or "exhaust leak" type noise at higher engine speeds, approximately 2,000-2,500 RPM, may indicate a loose or missing dampener. | Tighten the dampener retaining bolt or replace the torque tube assembly as required. | ||||||||
Incorrect gear oil in the transfer case | Replace with gear oil GM P/N 12378514 (Canadian P/N 88901045). | ||||||||
Bearing noise within the transfer case A "grinding" or "roar" type noise will increase or decrease relative to the vehicle speed. |
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Gear set "whine" noise within the transfer case "Whine" type noises will increase or decrease relative to the vehicle speed approximately 80-97 km/h (50-60 mph). |
Contributing factors may include:
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