The Eaton Detroit Truetrac is a helical gear-driven limited-slip differential that makes the most of available traction and sharpens handling and drivability. It works smoothly and automatically, needs no maintenance, and suits street, tow, and trail use without the on and off behavior of a locker. This unit fits the GM 8.5in 10-bolt rear axle with 28-spline shafts and 2.73 and up ratios.
- Type: Helical gear limited-slip differential
- Axle: GM 8.5in 10-bolt
- Ring gear diameter: 8.5in
- Axle shaft diameter: 1.20in
- Spline count: 28
- Gear ratio: 2.73 and up
- Part number: 912A556
Axle Fitment
- Fits the GM 8.5in 10-bolt rear axle, 28-spline, 2.73 and up ratios, found across 1972-1989 GM cars and 1/2-ton trucks. Confirm your axle and spline count.
FAQ
Will this fit my GM 8.5in 10-bolt axle?
It is built for the GM 8.5in 10-bolt rear axle with 28-spline shafts. Confirm your axle model and spline count before ordering.
What ratios does it work with?
It covers 2.73 and up (numerically higher) ring and pinion ratios.
Does the Truetrac need maintenance?
No. It is a fully automatic helical limited-slip that needs no maintenance and uses no clutch packs.
Is it a locker?
No. It is a limited-slip, so it stays smooth and quiet on the street without the on and off action of a locker.
