2020 Buick Envision BaseFACTORY OEM SERVICE PROCEDURE

Fastener Specifications

Power Transfer Unit Case and Components

Callout Component Name Single Use Fastener/Component Thread Locking Adhesive Required Specification Procedure
Metric (English)
1 Power Transfer Unit Alignment Sleeve Yes - - Power Transfer Unit Case Assemble 
2 Power Transfer Unit Cover Housing Seal Yes - - Power Transfer Unit Case Assemble 
3 Power Transfer Unit Face Seal Yes - - Power Transfer Unit Case Assemble 
4 Power Transfer Unit Half Shaft Retainer Clip Yes - - Power Transfer Unit Case Assemble 
5 Power Transfer Unit Half Shaft Seal O-Ring Yes - - Power Transfer Unit Case Assemble 
6 Power Transfer Unit Idler Gear Shaft Tube O-ring - Rear Yes - - Power Transfer Unit Case Assemble 
7 Power Transfer Unit Rear Output Shaft Seal Yes - - Power Transfer Unit Case Assemble 
8 Power Transfer Unit Input Shaft Seal - Front Yes - - Power Transfer Unit Case Assemble 
9 Power Transfer Unit Propeller Shaft Retainer Yes - - Power Transfer Unit Case Assemble 
10 Power Transfer Unit Drain Plug Yes Yes 40 N.m (30 lb ft) Power Transfer Unit Case Assemble 
11 Power Transfer Unit Fill Plug Yes Yes 40 N.m (30 lb ft) Power Transfer Unit Case Assemble 
12 Power Transfer Unit Cover Housing Bolt Yes - First Pass:
28 N.m (21 lb ft)
Final Pass:
90 degrees		 Power Transfer Unit Case Assemble 
13 Power Transfer Unit Case Bracket @ Engine - - 22 N.m (16 lb ft) Power Transfer Unit Case Assemble 
14 Power Transfer Unit Case Bracket @ Engine - - 58 N.m (43 lb ft) Power Transfer Unit Case Assemble 
15 Power Transfer Unit Case Bracket @ Extension Housing - - 22 N.m (16 lb ft) Power Transfer Unit Case Assemble 
16 Power Transfer Unit Case @ Transmission - - 100 N.m (74 lb ft) Power Transfer Unit Case Assemble 
17 Power Transfer Unit Vent Hose Connector - Yes 20 N.m (15 lb ft) Power Transfer Unit Case Assemble 
Factory Service Tools

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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.