Subaru OEM R180 3.545 Ring and Pinion Gear | 38104AA270

Overview

The Genuine Subaru OEM R180 3.545 Ring and Pinion Gear (Part #38104AA270) is a factory-original differential gear set engineered for Subaru vehicles equipped with the R180 rear differential. Designed for drivers seeking an exact-fit replacement or performance-oriented gear ratio swap, this OEM gear set restores factory drivetrain performance with uncompromising precision. As a genuine Subaru part, it delivers the same fit, finish, and durability as what came in your vehicle from the factory.

Key Features & Benefits

• Genuine Subaru OEM Quality — Manufactured to Subaru factory specifications, ensuring precise tolerances, proper mesh pattern, and long-term reliability that aftermarket gears cannot match.
• 3.545 Final Drive Ratio — Factory-correct gear ratio that maintains proper speedometer calibration, ABS function, and AWD system balance without the compromises of non-OEM alternatives.
• R180 Differential Compatibility — Engineered specifically for Subaru's R180 rear differential housing, guaranteeing a bolt-in fit with no machining or modification required.
• Factory-Grade Materials — Produced from high-strength alloy steel with precision heat treatment and surface finishing, delivering smooth, quiet operation and extended service life.
• Exact-Fit Guarantee — As a genuine Subaru part, this ring and pinion set installs without adaptation kits or shimming guesswork — fitment is validated by Subaru engineering.
• Covered by Subaru OEM Parts Warranty — Backed by Subaru's genuine parts warranty, providing peace of mind for your repair or build.

What's Included

• 1x Genuine Subaru OEM Ring Gear (3.545 ratio)
• 1x Genuine Subaru OEM Pinion Gear (3.545 ratio)

Specifications

Fitment & Compatibility

This ring and pinion gear set is designed for Subaru vehicles equipped with the R180 rear differential. The R180 differential is commonly found in the following Subaru platforms — confirm your specific differential code and gear ratio before ordering, as multiple ratio options exist across model years:

Important: Always verify your vehicle's differential carrier code and existing gear ratio against Subaru part number 38104AA270 before purchasing. Consult your Subaru dealer or parts catalog to confirm exact fitment for your year, model, and trim level.

Installation

Ring and pinion gear installation requires specialized tools including a differential bearing press, dial indicator, and torque wrench, as well as the correct shims and carrier bearings. Proper backlash and bearing preload setup is critical to differential longevity and quiet operation. Professional installation by a qualified drivetrain technician is strongly recommended. Always replace differential seals and carrier bearings during installation for best results.