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Detroit TrueTrac Detroit Truetrac Differential GM 10-Bolt

Detroit TrueTrac 912A556
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Detroit TrueTrac Detroit Truetrac Differential GM 10-Bolt $469.99
Detroit Truetrac Differential
  • GM 10-Bolt
  • 1971-89 GM Car
  • 1972-89 GM Truck
  • 28-Spline Axles
  • 8.5'' Diameter Ring Gear
  • Fits 2.73 & Up Gear Ratios
  • Rear Only

  • Detroit TrueTrac 912A556 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.

    Note: 1998 - Earlier use 873-D1585 Spool Bearings, 1999 - Later use 873-D1582 Spool Bearings


    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

  • 912A556 is rated 5.0 out of 5 by 2.
    Rated 5 out of 5 by from Customer for life... I can say so many great things about Jegs and my Detroit truetrac differential like how it is real posi trac. How fast they shipped it out. How good the item was described. How reasonable the price was. How impressive it works in my 86' Chevy C10 shortbox. I can go on and on but I'm just going to say that I am buying another one for my 85' shortbox. Thanks Jegs keep up the good work.
    Date published: 2016-03-28
    Rated 5 out of 5 by from Hooks hard! Been running this in a 6.0 equipped 86' c10 with the 10 bolt about a month and so far I really like it. No noise in corners. I really don't notice it's back there until it tries to spin then you can feel it grab and you're gone. I chose this over the Yukon posi and I think I made the right choice.
    Date published: 2016-02-25
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    Some parts are not legal for use in California or other states with similar laws / regulations