Oil Pump: Inspection

Oil Pump Housing, Oil Pump Cover, Inner Gear and Outer Gear 

• Check for wear or damage.

Side Clearances 

• Measure side clearance of inner and outer gears in at least four places around each outside edge. Maximum measured values should be within specified positions.
  1. Standard clearance: 0.030 - 0.050 mm (0.0012 - 0.0020 in) 
• If clearance is less than standard, select inner and outer gear as a set so that clearance is within specifications.
  1. Inner and outer gear: Refer to SDS,  REDUCTION PINION GEAR  . 
• If clearance is more than standard, replace whole oil pump assembly except oil pump cover.
  Fig 1: Measuring Side Clearance Of Inner And Outer Gears At Four Places

  Courtesy of NISSAN MOTOR CO., U.S.A.
• Measure clearance between outer gear and oil pump housing.
  1. Standard clearance: 111 - 0.181 mm (0.0044 - 0.0071 in) 
  2. Allowable limit: 0.181 mm (0.0071 in) 
• If not within allowable limit, replace whole oil pump assembly except oil pump cover.

Fig 2: Measuring Clearance Between Outer Gear And Oil Pump Housing

Courtesy of NISSAN MOTOR CO., U.S.A.

Seal Ring Clearance 

• Measure clearance between seal ring and ring groove.
  1. Standard clearance: 0.1 - 0.25 mm (0.0039 - 0.0098 in) 
  2. Allowable limit: 0.25 mm (0.0098 in) 
• If not within allowable limit, replace oil pump cover assembly.

Fig 3: Locating Clearance Between Seal Ring And Ring Groove

Courtesy of NISSAN MOTOR CO., U.S.A.