NISSAN 38151-01J1C Differential Adjusting Washer

This genuine NISSAN differential adjusting washer (part number: 38151-01J1C, alternative part number: 3815101J61) is a precision-machined calibration component made of hardened steel, essential for proper differential operation and long service life.

Function and Importance

The primary function of the differential adjusting washer is to accurately set the backlash and preload between the differential gears (particularly the pinion and ring gear). Proper shimming ensures that the gears mesh across an optimal contact pattern, minimizing friction, heat generation, and mechanical noise.

Technical Specifications

• Manufacturer: NISSAN (Genuine OEM part)
• OEM Part Number: 38151-01J1C
• Alternative / Interchange Part Number: 3815101J61
• Part Type: Differential adjusting washer / shim
• Material Quality: High wear-resistant, heat-treated, and hardened alloy steel for maximum dimensional stability under heavy loads.
• Application: Fine-tuning differential axial play and gear backlash.

Symptoms of Wear or Improper Shimming

Incorrect shim thickness or wear can lead to the following issues:

• Abnormal Noises: Whining, humming, or howling noise from the differential that intensifies with speed.
• Accelerated Wear: Uneven tooth contact, which can cause premature wear or tooth breakage on gears.
• Driveline Vibration: Vibrations originating from the propshaft or axle drive shafts.
• Metal Particles in Oil: Excessive friction caused by improper clearances releases metal shavings into the differential lubricant.

When repairing or assembling a differential, using adjusting washers that meet OEM specifications is mandatory to ensure driveline reliability.