Call Our Support Line
24 Hours / 7 Days a Week!  
Same Day Shipping Before 11 PM ET
My Cart
Shop By Vehicle
Shop By
Close Menu
Shop By Vehicle
Top Categories
All Categories

All Categories

Free Catalog
E-Mail Signup
My Account
Track Order
Gift Certificates

Detroit TrueTrac 912A557

Detroit Truetrac Differential GM 10-Bolt

Detroit TrueTrac 912A557
Representative Image
Product images may differ from actual product appearance.


made in usa
jegs shipping
FREE Shipping
Estimated ship date 12/21/17 if Ordered Today
Easy Returns
Easy Returns
Lowest Price Guarantee
Lowest Price Guarantee
Detroit TrueTrac 912A557 Detroit Truetrac Differential GM 10-Bolt $459.99
Detroit Truetrac Differential
  • GM 10-Bolt
  • 1977-88 GM Car/Truck
  • 28-Spline Axles
  • 8.5'' Diameter Ring Gear
  • Fits 2.73-5.13 Gear Ratios
  • Front Only

  • Detroit TrueTrac 912A557 Details

    GM 10-Bolt

    All GM 8.5"/8.6"Eaton differentials require special bearings. For 28 spline axles with small bearing bores (race O.D. of 2.89"), usually found on vehicles prior to 1999, bearing LM-102949 and race LM-102911 are required. For 30 spline axles with large bearing bores (race O.D. of 3.06"), usually found on vehicles from 1999 to present, bearing LM-603049 and race LM-603012 are required.


    Manufacturer's Part Number:

    The Detroit Truetrac is a helical-gear style performance differential that maximizes wheel traction and enhances driving and handling characteristics.

    The Truetrac operates as a standard or open differential under normal driving conditions, allowing one wheel to spin faster or slower as necessary. When a wheel encounters a loss of traction or the terrain changes, the gear separation forces take effect and transfer torque to the high-traction wheel. The helical-shaped gears mesh with increasing force until wheel spin is slowed or completely stopped. When the vehicle exits the low traction situation, the differential resumes normal operation.

    Operation of the Truetrac is smooth, quiet and automatic. The unit will engage without any driver knowledge or action required. It also has no wearable parts and requires no maintenance, meaning less time in the garage and more on the road.

  • Helical-style pinion gears
  • Limited-slip operation
  • Smooth and automatic engagement - no driver action needed
  • Parts are maintenance free meaning more time on the road
  • Validated performance and durability

  • Before you leave us... Receive a free catalog or join our email list

    Sign up to receive our catalog or subscribe to our email list now to see our exclusive email only specials, new products, and offers!

    Request CatalogJoin Email List