Disassembly and Assembly: Disassembly

Remove front timing chain case and timing chain. Refer to "REMOVAL AND INSTALLATION ".
Remove water pump. Refer to "VQ25HR: EXPLODED VIEW ".
Remove oil pan (upper). Refer to "2WD: EXPLODED VIEW " (2WD models) or "AWD: EXPLODED VIEW " (AWD models).
Remove rear timing chain case as follows:
1. Loosen mounting bolts in reverse order as shown in the figure.
  
  Fig 1: Identifying Tightening Sequence Of Front Timing Chain Case Mounting Bolts
  Courtesy of NISSAN NORTH AMERICA, INC.
2. Cut liquid gasket using the seal cutter [SST: KV10111100] and remove rear timing chain case.
  CAUTION:
  - Never remove plate metal cover (1) of oil passage.
  - After removal, handle rear timing chain case carefully so it does not tilt, cant, or warp under a load.
  Fig 2: Identifying Plate Metal Cover Of Oil Passage
  Courtesy of NISSAN NORTH AMERICA, INC.
Remove O-rings (1) from cylinder block.

Fig 3: Identifying Cylinder Block O-Ring
Courtesy of NISSAN NORTH AMERICA, INC.
Remove timing chain tensioners (secondary) from cylinder head as follows, if necessary.
1. Remove camshaft brackets (No. 1). Refer to "EXPLODED VIEW ".
2. Remove timing chain tensioners (secondary) with a stopper pin (A) attached.
  
  Fig 4: Pushing Plunger Of Timing Chain Tensioner (Secondary) Using Stopper Pin
  Courtesy of NISSAN NORTH AMERICA, INC.