USA Standard Axle For 8.2in & 8.5in GM Passenger Car. 30 1/8in Long / 28 Spline / 2.780in Hub

Precision-Machined Rear Axle Shaft for GM 8.2in and 8.5in Passenger Cars Including Camaro, Chevelle, Monte Carlo, and Firebird

The ZA G1255802-SH from USA Standard Gear is a high-quality replacement rear axle shaft designed for General Motors 8.2in and 8.5in semi-floating rear differentials found in a wide range of classic GM passenger cars. Measuring 30 1/8 inches in length with a 28-spline count and a 2.780-inch brake pilot, this shaft is a precision-machined drop-in replacement that restores the drivetrain integrity of your Camaro, Chevelle, Monte Carlo, or Firebird. Constructed from 1541H alloy steel, the ZA G1255802-SH provides the tensile strength and fatigue resistance appropriate for performance-oriented classic car applications.

This shaft fits applications using the GM 8.2in or GM 8.5in rear axle housing. Confirming your axle tube diameter and spline count before installation ensures a correct fit. USA Standard Gear backs the ZA G1255802-SH with a 10-year limited warranty against manufacturer defects, reflecting the brand's commitment to quality drivetrain components.

What's Included

• 1 x USA Standard Gear ZA G1255802-SH Rear Axle Shaft

Specifications

Vehicle Fitment

Why Choose USA Standard Gear for Your Classic GM Build

USA Standard Gear is a Yukon Gear and Axle brand that has been supplying quality drivetrain parts to the performance and restoration market for decades. Classic muscle car and pony car restorers trust USA Standard axle shafts because dimensional tolerances are held precisely to OEM specifications. The 1541H alloy steel used in this shaft is the same grade used in many OEM axle applications, offering a reliable, long-lasting replacement that holds up to spirited street driving and occasional track use.

Frequently Asked Questions

What classic GM vehicles does this shaft fit?
This shaft fits 1968 to 1973 Chevrolet Chevelle, 1970 to 1973 Chevrolet Monte Carlo, 1970 to 1981 Chevrolet Camaro, and 1970 to 1981 Pontiac Firebird vehicles equipped with the GM 8.2in or GM 8.5in semi-floating rear axle where the 30 1/8-inch shaft length applies.

What distinguishes this shaft from other GM 8.5in axle shafts?
The ZA G1255802-SH is dimensioned at 30 1/8 inches with a 28-spline profile and a 2.780-inch brake pilot. Different GM applications use different lengths and spline counts, so always verify the length and spline count of your original shaft before ordering a replacement.

Does this shaft fit both the GM 8.2in and the GM 8.5in axle housing?
Yes. This shaft is designed to fit both GM 8.2in and GM 8.5in semi-floating rear axle housings when the length and spline specifications match. Confirm axle identification on your specific vehicle before ordering.

Will this shaft work in a Camaro equipped with a Positraction limited-slip differential?
Yes. The shaft splines into the carrier side gear and is not affected by whether the carrier is an open unit or a Positraction limited-slip. The 28-spline specification must match your carrier's side gear spline count.

What is the brake pilot diameter on this shaft?
The brake pilot is 2.780 inches, which is the correct size for the drum brake applications used on these classic GM cars.

What material is used in this shaft?
This shaft is produced from 1541H alloy steel. The elevated manganese content in this alloy improves hardenability and resistance to bending fatigue under load.

How do I identify whether my classic car has the GM 8.2in or 8.5in rear axle?
The GM 8.2in rear axle was commonly used in earlier applications through the late 1960s and into the early 1970s. The GM 8.5in became more prevalent from the early 1970s onward. Differential cover bolt count and ring gear diameter are the most reliable ways to distinguish between the two. You can also reference the axle tag or a GM casting number guide for your specific vehicle.

What warranty does the ZA G1255802-SH carry?
USA Standard Gear provides a 10-year limited warranty against manufacturer defects on this shaft. This warranty complies with the requirements of the Magnuson-Moss Warranty Act. Retain your proof of purchase for any warranty claims.

Can this shaft be used in a street-strip or drag racing application?
This is a quality street-replacement shaft. For high-horsepower drag racing applications, evaluate whether a heavy-duty or chromoly axle shaft would better suit the power level and launch forces involved.

Installation Instructions

1. Raise the vehicle and support it securely on jack stands at the rear axle. Remove the wheel on the side being serviced.
2. Remove the brake drum or disc brake components as applicable for your vehicle's brake configuration.
3. Remove the differential cover and drain the gear oil.
4. Locate and remove the pinion shaft retaining bolt, then slide the pinion shaft out of the carrier.
5. Push the axle shaft inward slightly to expose the C-clip groove at the inner end of the shaft. Remove the C-clip.
6. Slide the old shaft carefully out of the housing. Inspect the axle seal and bearing for wear and replace as needed.
7. Insert the ZA G1255802-SH into the axle tube, engaging the splines with the carrier side gear. Push inward until the C-clip groove is accessible inside the differential.
8. Install the C-clip and pull the shaft outward to fully seat the C-clip against the side gear.
9. Reinstall the pinion shaft and lock bolt to factory torque specification.
10. Clean the differential cover sealing surface and reinstall the cover with new gasket material or RTV sealant.
11. Refill the differential with the correct type and quantity of gear oil per the vehicle manufacturer's specification.
12. Reinstall the brake components and wheel. Torque lug nuts to specification.
13. Lower the vehicle and test drive, then inspect for any leaks at the differential cover.