Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2020 GMC Terrain SLFACTORY OEM SERVICE PROCEDURE
Power Transfer Unit/Transfer Case - AAM
- Specifications
- Visual Identification
- Diagnostic Information and Procedures
- Repair Instructions - On Vehicle
- Power Transfer Unit Case Fluid Replacement
- Drain Plug Replacement
- Fill Plug Replacement
- Power Transfer Unit Vent Hose Replacement
- Power Transfer Unit Shift Actuator Replacement
- Power Transfer Unit Cover to Intermediate Drive Shaft Seal Replacement
- Output Shaft Seal Replacement
- Power Transfer Unit Face Seal Replacement
- Transmission Brace Replacement (MNH Transmission With LYX Engine)
- Transmission Brace Replacement (M3D, M3H Transmission with LTG Engine)
- Power Transfer Unit Case Replacement (MNH Transmission with LYX Engine)
- Power Transfer Unit Case Replacement (M3D Transmission with LTG Engine)
- Power Transfer Unit Heat Shield Replacement (M3D transmission with LTG engine)
- Repair Instructions - Off Vehicle
- Power Transfer Unit Case Disassemble
- Power Transfer Unit Case Holding Fixture Installation
- Power Transfer Unit Oil Fill Plug, Oil Drain Plug, and Vent Hose Connector Removal
- Power Transfer Unit Intermediate Drive Shaft Components Removal
- Power Transfer Unit Propeller Shaft Seal, O-ring and Retainer Removal
- Power Transfer Unit Actuator, Seal and Bolt Removal
- Power Transfer Unit Extension Housing, Cover Housing Seal and Bolt Removal
- Power Transfer Unit Input Shaft, Idler Shaft, and Idler Shaft Tube Removal
- Power Transfer Unit Alignment Sleeve, Face Seal, Input Shaft Seal and Idler Gear Shaft Tube O-ring Removal
- Power Transfer Unit Input Shaft Seal and Idler Gear Shaft Tube O-ring Removal
- Power Transfer Unit Case Cleaning and Inspection
- Power Transfer Unit Case Assemble
- Power Transfer Unit Input Shaft Seal, Idler Gear Shaft Access Tube and Idler Gear Shaft Tube O-ring Installation
- Power Transfer Unit Alignment Sleeve, Face Seal, Input Shaft Seal and Idler Gear Shaft Tube O-ring Installation
- Power Transfer Unit Input Shaft and Idler Shaft Assembly Installation
- Power Transfer Unit Extension Housing, Cover Housing Seal and Bolt Installation
- Power Transfer Unit Actuator, Seal and Bolt Installation
- Power Transfer Unit Propeller Shaft Seal, O-ring and Retainer Installation
- Power Transfer Unit Intermediate Drive Shaft Components Installation
- Power Transfer Unit Cover-to-Intermediate Drive Shaft Seal, Half Shaft O-ring Seal and Retainer Installation
- Power Transfer Unit Oil Fill Plug, Oil Drain Plug, and Vent Hose Connector Installation
- Power Transfer Unit Case Holding Fixture Removal
- Power Transfer Unit Case Disassemble
- Description and Operation
- Special Tools and Equipment
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.