Detroit Truetrac Limited-Slip Differential for 8.875 in. Rear Axle [30 Spline, 3.08-3.90 Ratio]
InfoVehicle Info Needed
DETROIT TRUETRACPART NUMBER: 363-913A555

Detroit Truetrac Limited-Slip Differential for 8.875 in. Rear Axle [30 Spline, 3.08-3.90 Ratio]

$64529$716.99You Save$71.70
ShippingShips on 11/05/2026
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GM 12-Bolt
Helical Gear Limited-Slip Differential
  • 8.875 in. Rear Axle Housing
  • 30 Spline
  • 3.08-3.90 Ratio Ring Gear Pinion Ratio
  • 1.29 in. Axle Shaft Diameter
  • Sold Individually

    A open differential sends all available torque to whichever rear wheel has the least grip, which is exactly the wheel that spins first on a wet road, a dirt trail, or a hard launch. The Detroit Truetrac replaces the open differential with a helical-gear limited-slip design that biases torque to the wheel with traction automatically, with no clutches or cones to wear out and no on-off engagement feel in daily driving.

    Eaton 913A555 Features:

    • Helical-gear design engages automatically in both forward and reverse with no clutches, cones, or friction modifiers to wear out.
    • Fits 8.875 in. rear axle housings.
    • 30 spline output with a 1.29 in. axle shaft diameter.
    • Covers 3.08-3.90 Ratio ring gear pinion ratio range.
    • Maintenance-free operation - no special lubricants or friction modifiers required.
    • Smooth, quiet engagement with no on/off feel or driveline shock.
    • Enhance Your Vehicle's Driving Experience with a Trutrac Differential

      The Detroit Truetrac is a helical-gear-style performance differential that maximizes wheel traction and enhances driving and handling characteristics. These units operate as a standard or open differential under normal driving conditions and are smooth, quiet, and automatic. They will engage without any driver's knowledge or action required providing worry-free performance.

    Part TypeDifferential Carrier
    Product LineDetroit Truetrac Differentials
    BrandDETROIT TRUETRAC
    Package Height8.2
    Package Width8.2
    Package Length8.7
    Weight27.5 PG
    Part CategoryPerformance Parts
    Axle Shaft Diameter1.29 in.
    PositionRear
    Ring Gear Pinion Ratio Range3.08 - 3.90
    Spline Count30
    Differential TypeHelical Gear Limited Slip
    Part FitmentDirect Fit
    Axle Housing Size8.875 in.
    Vendor Part Number913A555
    Package Qty1
    Package TypeEA
    No Questions
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