Transfer Case Clunk in 4LO. GMC Truck Sonoma Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2002 🢒 Sonoma Pickup - 4WD 🢒 Driveline/Axle 🢒 Transfer Case - NVG 233-NP1 (Two Speed Selectable) 🢒 Transfer Case Clunk in 4LO

Cause

Correction

DEFINITION: During acceleration or deceleration a clunk is heard or felt in the transfer case.

Review the Symptoms - Transfer Case and perform the necessary inspections.

Incorrect fluid level or incorrect fluid

•	Inspect the transfer case for the correct fluid level. Refer to Transfer Case Fluid Replacement .

•	Fill the transfer case to the correct fluid level, if required.

•	Inspect the transfer case for the correct type of fluid.

•	Flush the transfer case and fill with the correct fluid, if required.

Worn planetary gears

Inspect for excessive worn planetary gears. Refer to Transfer Case Assemble in Transmission/Transaxle/Transfer Case Unit Repair Manual.

Synchronizer clutch gear loose on the mode sleeve

Inspect the spline fit of the clutch gear to the mode sleeve for excessive clearance. Refer to Transfer Case Cleaning and Inspection in Transmission/Transaxle/Transfer Case Unit Repair Manual.

Replace the clutch gear and the mode sleeve if the clearance is excessive. Refer to Transfer Case Assemble in Transmission/Transaxle/Transfer Case Unit Repair Manual.

Synchronizer hub loose on the mainshaft

Inspect the spline fit of the synchronizer hub to the mainshaft for excessive clearance. Refer to Transfer Case Cleaning and Inspection in Transmission/Transaxle/Transfer Case Unit Repair Manual.

Replace the synchronizer assembly and the mainshaft if the clearance is excessive. Refer to Transfer Case Assemble in Transmission/Transaxle/Transfer Case Unit Repair Manual.