Transfer Case Will Not Shift

WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
DEFINITION: While shifting from HI range to LO range, there is gear clashing or the gear range cannot be selected. Review the Symptoms - Transfer Case and perform the necessary inspections.
High/low shift fork spring assembly	Inspect the high/low shift fork spring assembly for the following conditions: Worn high/low shift fork pin Worn cam Broken spring Refer to High/Low Shift Components Cleaning and Inspection . Replace the following components if found faulty: The high/low shift fork spring assembly The high/low shift fork pin Refer to High/Low Shift Fork Replacement .
High/low shift fork	Inspect the high/low shift fork for the following conditions: Worn shift fork pads Cracked or bent shift fork Refer to High/Low Shift Components Cleaning and Inspection . Replace the following components if found faulty: The shift fork pads The shift fork Refer to High/Low Shift Fork Replacement .
High/low clutch	Inspect the high/low clutch for the following conditions: Engagement teeth for burrs or damage Sliding freely on the rear output shaft The high/low clutch collar for excessive wear Refer to High/Low Shift Components Cleaning and Inspection . Replace the high/low clutch if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Input shaft pilot bearing assembly	Inspect for the following conditions: Failed bearing in the input shaft Journal on the rear output shaft for excessive wear or damage Refer to Rear Output Shaft Cleaning and Inspection and Front Output Shaft and Input Shaft Cleaning and Inspection . Replace the bearing if faulty. Refer to Input Shaft Pilot Bearing Replacement (Light Duty) or Input Shaft Pilot Bearing Replacement (Heavy Duty and Super Heavy Duty) . Replace the rear output shaft if damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble .
High/low planetary carrier assembly	Inspect the high/low planetary engagement teeth for burrs or damage. Refer to High/Low Planetary Carrier Cleaning and Inspection . Replace the high/low planetary carrier assembly if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .