Nissan Sentra B18 (2020-2025) Service Manual: Oil Seal

Valve Oil Seal

Removal and Installation

Removal and Installation

REMOVAL

Remove camshafts. Refer to Removal and Installation.

Remove valve lifters. Refer to Exploded View.

Rotate crankshaft and set piston whose valve oil seal is to be removed to TDC. This will prevent valve from dropping into cylinder.

CAUTION:

When rotating crankshaft, be careful to avoid scarring front cover with timing chain.

Compress the valve spring with suitable tool (A/B/C) and remove the valve collet with a suitable magnetic tool.

CAUTION:

• Do not damage valve lifter holes.

• The center of suitable tool (A) and valve spring retainer (1) must be aligned.

  

Remove valve spring retainer and valve spring (with valve spring seat).

CAUTION:

Do not remove valve spring seat from valve spring.

Remove valve oil seal with suitable tool (A).

INSTALLATION

Apply new engine oil to valve oil seal joint surface and seal lip.

Press in valve oil seal using suitable tool (A) to the specified height (H).

Height (H)

: 15.1 - 15.7 mm (0.594 - 0.618 in)

Installation of the remaining components is in the reverse order of removal.

Front Oil Seal

Removal and Installation

Removal and Installation

REMOVAL

Remove the front fender protector (RH). Refer to Removal and Installation.

Remove crankshaft pulley using the following procedure: Secure crankshaft pulley (1) with a suitable tool (A) and loosen crankshaft pulley bolt.

CAUTION:

Do not remove the crankshaft pulley bolt as it is used as a supporting point for a suitable puller.

Attach a suitable puller (A) in the threaded hole on crankshaft pulley (1) and remove crankshaft pulley.

Remove front oil seal with a suitable tool.

CAUTION:

• Do not damage front cover and crankshaft.

• Do not reuse front oil seal.

INSTALLATION

Apply new engine oil to new front oil seal joint surface and seal lip.

CAUTION:

Do not reuse front oil seal.

Install front oil seal so that each seal lip is oriented as shown.

(A)	: Dust seal lip
(B)	: Oil seal lip
	: Engine outside
	: Engine inside

• Press-fit front oil seal using a suitable drift with outer diameter 57 mm (2.24 in) and inner diameter 45 mm (1.77 in).

  CAUTION:

  • Do not damage front cover or crankshaft.

  • Press-fit front oil seal straight to avoid causing burrs or tilting.

  Note:

  Front oil seal (2) should be installed within the range shown from the front face (A) of the front cover (1).

  

  Dimension (B)	: 0.3 mm (0.012 in)
  Dimension (C)	: 0.5 mm (0.020 in)

  : Engine front

Install crankshaft pulley using the following procedure: When inserting crankshaft pulley with a suitable tool, tap on its center portion (not circumference).

CAUTION:

Do not damage front oil seal lip portion.

Secure crankshaft pulley (1) with a suitable tool (A). Apply new engine oil to thread and seat surfaces of crankshaft pulley bolt. Tighten crankshaft pulley bolt to the specified torque.

Crankshaft pulley bolt

: 29.4 N·m (3.0 kg-m, 22 ft-lb)

Put a paint mark (B) on crankshaft pulley (2), matching with any one of six easy to recognize angle marks (A) on crankshaft pulley bolt (1) flange. Tighten crankshaft pulley bolt to the specified angle using Tool.

• Check the tightening angle with movement of one angle mark.

  CAUTION:

  Check and confirm the tightening angle using Tool. Avoid judgement by visual inspection without Tool.

  Tool number

  : KV10112100 (BT-8653-A)

  Tightening angle

  : 60° - 66°

Check that crankshaft rotates clockwise smoothly.

Installation of the remaining components is in the reverse order of removal.

Rear Oil Seal

Removal and Installation

Removal and Installation

REMOVAL

Remove the drive plate or flywheel. Refer to Removal and Installation (CVT models) or Removal and Installation (M/T models).

Remove rear oil seal with a suitable tool.

CAUTION:

• Do not damage crankshaft or cylinder block.

• Do not reuse rear oil seal.

INSTALLATION

Install rear oil seal so that each seal lip is oriented as shown.

CAUTION:

Do not reuse rear oil seal.

(A)	: Dust seal lip
(B)	: Oil seal lip
	: Engine outside
	: Engine inside

• Press-fit rear oil seal with a suitable drift (A) outer diameter 115 mm (4.53 in) and inner diameter 90 mm (3.54 in).

  

  CAUTION:

  • Do not damage crankshaft or cylinder block.

  • Press-fit rear oil seal straight to avoid causing burrs or tilting.

  • Do not touch grease applied onto oil seal lip.

• Press in rear oil seal (1) to the position as shown.

  

  Dimension (b)

  : -0.3 - 0.05 mm (-0.012 in - 0.020 in)

  (A)	: Rear end surface of cylinder block

Installation of the remaining components is in the reverse order of removal.