TOYOTA 90564-40011 Differential Pinion Shim

The genuine Toyota differential pinion shim, part number 90564-40011, is a critical precision component within the vehicle's drivetrain. Its purpose is to achieve micrometer-level adjustment of the drive pinion depth, ring-and-pinion gear backlash, and bearing preload.

Proper shimming is essential to ensure optimal gear tooth mesh contact, quiet operation, and extended differential service life. Incorrect shimming can cause premature wear, broken gear teeth, or total differential failure.

Technical Characteristics and Specifications:

• Manufacturer: Toyota (Genuine OEM part)
• OEM Part Number: 90564-40011
• Interchange / Alternative Part Numbers: 9020140554
• Part Type: Differential Pinion Shim
• Material: High-strength, hardened precision steel resistant to heavy axial loads and gear lubricants

Function and Symptoms of Wear:

During differential assembly or rebuilding, shims are used to accurately set the axial position of the drive pinion. If shimming is inaccurate or a shim becomes worn, the following symptoms may occur:

• Whining, howling, or rumbling noise from the differential, especially under acceleration or engine braking.
• Abnormal, uneven tooth contact patterns on the pinion and ring gear.
• Metal particles or shavings found in the differential gear oil.
• Excessive backlash/play in the driveline.

When overhauling the differential or replacing bearings, inspecting and replacing shims as required is strictly mandatory to restore factory-correct specifications and operation.