1978 Pontiac Firebird Differentials

Keep Your 1978 Pontiac Firebird in Top Shape with Quality Differentials

Whether you’re repairing or upgrading your Differential, using high-quality parts is key to keeping your 1978 Pontiac Firebird looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Rear Housing Cover Gaskets, Differential Oil, and Differential Bearings. Whether you’re replacing a damaged part or enhancing your truck’s style and protection, you’ll find exactly what you need to get the job done right.

Top-Rated Differentials from Trusted Brands

Looking for a reliable Differential? We’ve got you covered with options from brands you know and trust like National, Motive Gear, and DriveWorks. For example, National Differentials start at just $7.99 with an average 4.3 star rating. Motive Gear and DriveWorks offer similar pricing and quality, backed by strong customer feedback. With over 3,156 reviews and a solid 4 star average, you can shop with confidence knowing other Pontiac Firebird owners approve.

Competitive Prices and Extensive Inventory

The average price for a 1978 Pontiac Firebird Differential at Advance Auto Parts is around $212.72, with a range that starts at $2.59 and goes up to $1,153.99. With 267 options in stock from 14 trusted brands, finding the right fit is easy. Popular picks like DEXRON – VI ATF Full Synthetic Automatic Transmission Fluid, 1 Quart, DEX/MERC ATF Conventional Automatic Transmission Fluid, 1 Quart, and Differential Shaft Lock Bolt start at just $6.79 and offer a great balance of form and function.

Explore Related Parts

While you’re upgrading or replacing your Differential, don’t forget to check out other key components like Drive Shafts and Axles and Universal Joints. At Advance Auto Parts, we’re here to help you keep your 1978 Pontiac Firebird in peak condition, inside and out.

Essential 1978 Pontiac Firebird Differentials

Dorman – Help – Differential Shaft Lock Bolt (Part No.81048)

Differential Shaft Lock Bolt

from

$6.79
This differential pinion shaft lock bolt is designed to match the fit and function of the original part on specified vehicles. Made of quality materials, it is engineered for reliable performance.

Product Features:
  • Direct replacement – this differential pinion shaft lock bolt matches the fit and function of the factory part on specified years, makes and models
  • Ideal solution – this bolt is a reliable replacement for an original part that is missing or has failed due to fatigue
  • Durable construction – this part is made from quality materials to ensure reliable performance and long service life
  • Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience
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Yukon Gear – 14 Plate Carbon Clutches For GM 8.2", GM 8.5", 12T, 12P, Ford 8.8" & Cast Iron ‘Vette (Part No.16041)

14 Plate Carbon Clutches For GM 8.2", GM 8.5", 12T, 12P, Ford 8.8" & Cast Iron 'Vette

from

$404.99
Product Features:
  • Clutch kit
  • Fits Ford 8.8″, 1963-1979 Corvette, GM 12 bolt passenger car and truck, 8.2″, 8.5″ and 8.6″ Dura Grip positraction
  • 14 piece kit
  • Carbon fiber clutches
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Yukon Gear – Pinion Install Kit For GM 8.2" Differential For Buick, Pontiac, And Oldsmobile (Part No.13068)

Pinion Install Kit For GM 8.2" Differential For Buick, Pontiac, And Oldsmobile

from

$282.99
Yukon Pinion installation kits are a terrific solution for gear installation on lower mileage vehicles where the carrier bearings & races can be reused. This kit uses Timken bearings and races along with a high quality pinion seal and small parts. Included in this kit are the pinion bearings and races, pilot bearing (if applicable), crush sleeve (if applicable), complete pinion shim kit, thread locker, and marking compound with brush. Yukon does extensive research for each application to make sure your kit will arrive with all the correct parts you need to install your pinion gear.

Product Features:
  • Fits 8.2″ Buick, Oldsmobile and Pontiac
  • Included are pinion bearings and races, pinion seal, crush sleeve, complete pinion shim kit, and marking compound with brush.
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Felpro – Axle Housing Cover Gasket Irregular Shaped 12 Bolt Hole Gasket (Part No.RDS 55009)

Axle Housing Cover Gasket Irregular Shaped 12 Bolt Hole Gasket

from

$9.29
Fel-Pro® gaskets are specifically designed for the repair environment to deliver a reliable seal on even the most troublesome applications. Designed for imperfect sealing surfaces and manufactured with proprietary materials, you can count on Fel-Pro for innovative sealing solutions for the real-world repair environment.

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered for the sealing repair environment
  • Validated for fit, form and function
  • Unsurpassed quality you can trust
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USA Standard Gear – Master Overhaul Kit for the GM 8.5 Differential (Part No.37055)

Master Overhaul Kit for the GM 8.5 Differential

from

$206.99
USA Standard Master Overhaul kits let you finish your install with confidence. This kit uses Koyo bearings and races. Included are carrier bearings and races, pinion bearings and races, pinion seal, complete shim kit, ring gear bolts, pinion nut, crush sleeve (if applicable), oil baffles and slingers (if applicable), threading locking compound, marking compound with brush and gasket.

Product Features:
  • Fits GM 8.5″ rear
  • Uses Koyo bearings and races
  • Included are carrier bearings and races, pinion bearings and races, pinion seal, complete shim kit, ring gear bolts, pinion nut, crush sleeve, thread locker, marking compound with brush and gasket.
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Powertrax – No-Slip Traction System (Part No.9207752605)

No-Slip Traction System

from

$518.99
For vehicles that are driven daily, the Powertrax No-Slip Traction System is the latest design in quiet traction-adding differential technology. It combines the automatic street-friendly smooth operation of a limited-slip differential with the traction performance of a locking differential. The Powertrax No-Slip locker easily installs in to your differential carrier using basic tools and without affecting your ring and pinion settings. Powertrax Grip-Lok, Lock-Right Lockers and No-Slip Traction Systems automatically provide 100% traction on-demand, under the toughest circumstances. The Powertrax Grip-Pro and Grip-LS performance limited slips offer smooth dependable torque transfer and traction for the best of both worlds!The Powertrax® Lock-Right Locker provides outstanding traction for off-road machines and race vehicles. Powertrax No-Slip Traction Systems deliver excellent performance to street-driven cars and trucks.
  • Powertrax® lockers range from the original, Lock-Right for serious straight-line performance, to the No-Slip traction system for street-able vehicles.
  • Powertrax® offers three levels of GRIP locking differentials, ranging from the clutch-type GRIP LS with a forged steel case, the gear-driven GRIP PRO and finally the GRIP LOK for extreme traction.
  • Powertrax® = Extreme Traction Systems!
  • See More

    Yukon Gear – Dura Grip Positraction For GM 8.5" With 28 Spline Axles (Part No.26015)

    Dura Grip Positraction For GM 8.5" With 28 Spline Axles

    from

    $859.99
    The Yukon Dura Grip provides aggressive yet smooth traction to give you the confidence & performance you need. Get longer life and better traction with the heavy duty Yukon Dura Grip Positraction. The Yukon Dura Grip uses a nodular case and forged 4320 internals for added strength along with composite clutches for high performance and long life. All units are Rebuildable and many offer upgrades to increase aggressiveness for racing applications. Each unit carries a one year warranty against defects. This unit has larger bearing journals for added strength & uses heavy-duty carrier bearings & races.

    Product Features:
    • Fits GM 8.5″ with 28 spline axles
    • 2.73 ratio and up only
    • 4-spring, clutch style positraction
    • Internal gears are manufactured using forged 4320 steel and cut to provide stronger teeth
    • Fully rebuildable
    • Assembled in the USA
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    Yukon Gear – The Carrier Bearing Puller (Part No.56072)

    The Carrier Bearing Puller

    from

    $883.99
    The Yukon carrier bearing Puller works with an impact gun to quickly and safely remove carrier bearings without damaging them. This unit comes with a handy bench top stand and works with up to one ton applications including Dana 70HD, Dana 80, 10.25″ & 10.5″ Ford, or GM & Chrysler 11.5″ differentials.

    Product Features:
    • Carrier bearing puller
    • Works with an impact gun to safely and easliy remove carrrier bearings
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    USA Standard Gear – Spider Gear Kit For GM 12 Bolt Car And Truck (Part No.39021)

    Spider Gear Kit For GM 12 Bolt Car And Truck

    from

    $161.99
    Product Features:
    • Spider gear kit
    • Fits GM 12 bolt passenger car and truck open differential with 30 spline axles
    • Includes two side gears, two pinion gears, cross pin shaft, cross pin bolt and spider gear thrust washers.
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    Powertrax – No-Slip Traction System (Part No.9207822801)

    No-Slip Traction System

    from

    $544.99
    For vehicles that are driven daily, the Powertrax No-Slip Traction System is the latest design in quiet traction-adding differential technology. It combines the automatic street-friendly smooth operation of a limited-slip differential with the traction performance of a locking differential. The Powertrax No-Slip locker easily installs in to your differential carrier using basic tools and without affecting your ring and pinion settings. Powertrax Grip-Lok, Lock-Right Lockers and No-Slip Traction Systems automatically provide 100% traction on-demand, under the toughest circumstances. The Powertrax Grip-Pro and Grip-LS performance limited slips offer smooth dependable torque transfer and traction for the best of both worlds!The Powertrax® Lock-Right Locker provides outstanding traction for off-road machines and race vehicles. Powertrax No-Slip Traction Systems deliver excellent performance to street-driven cars and trucks.
  • Powertrax® lockers range from the original, Lock-Right for serious straight-line performance, to the No-Slip traction system for street-able vehicles.
  • Powertrax® offers three levels of GRIP locking differentials, ranging from the clutch-type GRIP LS with a forged steel case, the gear-driven GRIP PRO and finally the GRIP LOK for extreme traction.
  • Powertrax® = Extreme Traction Systems!
  • See More

    Yukon Gear – Replacement Bare Case For GM 8.5" & 8.6" Dura Grip (Part No.20107)

    Replacement Bare Case For GM 8.5" & 8.6" Dura Grip

    from

    $386.99
    Replacement bare case for GM 8.5″ & 8.6″ Yukon Dura Grip. Fits both 28 & 30 spline applications. This carrier case is for a Yukon Dura Grip ONLY. It is NOT a replacement carrier for a stock positraction.

    Product Features:
    • Dura Grip positraction carrier case
    • Does not include spider gears
    • Fits GM 8.5″ and 8.6″
    • Fits 2.76 and up ratios only
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    Yukon Gear – Carrier Installation Kit For GM 8.5" Differential With HD Bearings (Part No.57009)

    Carrier Installation Kit For GM 8.5" Differential With HD Bearings

    from

    $148.99
    Yukon Carrier installation kits are great, low cost kit for carrier changes such as Positraction or locker upgrades. Carrier installation kit for GM 8.5″ differential with HD bearings for large journal carrier. This kit contains carrier bearings, races and shims. This kit is used in 8.5″ differentials using a Yukon Dura Grip, Eaton posi, ValueTrac, True Trac, Pro-Series Auburn, Detroit Locker or standard carrier with large bearing journals.

    Product Features:
    • Fits GM 8.5″ with aftermarket positraction
    • Works with Heavy Duty Bearings
    • Includes carrier bearings and races and “super” carrier shim kit
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    Yukon Gear – Positraction Pinion Gear Thrust Washer With Step-Lip Inside For GM 12P And 12T – Fits New Eatons (Part No.33382)

    Positraction Pinion Gear Thrust Washer With Step-Lip Inside For GM 12P And 12T - Fits New Eatons

    from

    $14.99
    Positraction pinion gear thrust washer with step-lip inside for GM 12P and 12T. fits new Eatons.

    Product Features:
    • Pinion gear thust washer for GM 12 bolt passenger car and truck
    • Fits positraction designs only
    • Has inside lip
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    Motive Gear – Differential Gear Install Kit (Part No.GM8.5PIK)

    Differential Gear Install Kit

    from

    $59.99


    Product Features:
    • 8.5 “P” AXLE MINI INSTALL KIT
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    Motive Gear – Differential Bearing Kit – Koyo (Part No.R8.5PR)

    Differential Bearing Kit - Koyo

    from

    $94.99
    Motive Gear Differential Bearing Kits Include Front & Rear Pinion Bearing, Pinion Seal, Carrier Bearings, Pilot Bearing Where Applicable, Gear Marking Compound, Crush Sleeve, Pinion Nut, Brush, Thread Locking Compound And Cover Gasket Or Rtv

    Product Features:
    • BRG & SEAL KIT-10 BOLT “P” AXLE
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    Pro-King – Shim Kit (Part No.741A200)

    Shim Kit

    from

    $19.99
    Pro-King is the leading supplier of transmission and driveline products in the aftermarket.

    Product Features:
    • All products are designed to meet or exceed OE quality, form, fit and funtion.
    See More

    National – Bearing Race (Part No.LM501314)

    Bearing Race

    from

    $9.29
    Manufactured with premium-grade steel, National taper bearing cups feature crowned raceways to ensure even load distribution.

    Product Features:
    • PREMIUM MATERIALS – Precision manufactured using premium-grade steel for outstanding durability and performance
    • SMOOTH ROTATION – Crowned raceways for even load distribution
    • OE-STYLE DESIGN – Engineered to meet OE specifications
    • COMPREHENSIVE COVERAGE – Industry-leading coverage for domestic and import applications
    • RIGOROUS TESTING – Comprehensive testing throughout design and development processes by National engineers for quality you can count on
    See More

    Motive Gear – Crush Sleeve (Part No.1234726)

    Crush Sleeve

    from

    $4.99
    Motive Gear offers some of the toughest drive train components on the market today. If you are looking for the largest line of performance ring and pinion gear options available with gear sets in a wide range of ratios for nearly every application, both on and off-road, check out Motive Gear. Motive Gear products can be found in the winner’s circle at racing events worldwide. The superior quality of Motive Gear components is the result of years of racing development, outstanding design and state-of-the-art manufacturing methods. Extensive testing is performed on all products by our in-house engineers.
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    Pro-King – Differential Cover Plug (Part No.742G484)

    Differential Cover Plug

    from

    $6.99
    Pro-King is the leading supplier of transmission and driveline products in the aftermarket.

    Product Features:
    • All products are designed to meet or exceed OE quality, form, fit and funtion.
    See More

    Richmond Gear – Differential Cross Shaft (Part No.CSPGM75)

    Differential Cross Shaft

    from

    $26.49
    Richmond Gear is the leading manufacturer of professional quality, high-performance drivetrain products. Our complete line of products ranges from high performance ring-and-pinion sets for serious street and racing applications to torque-hungry manual transmissions and components. Richmond Gear products have been winners both at the Daytona 500 and U.S. Nationals for decades. WINNERS RUN RICHMOND!

    Product Features:
    • For over 80-years, the Richmond Double-Diamond logo has represented some of the highest quality gears in the racing industry. Winners Run Richmond!
    • The superior quality of Richmond gearsets is a result of outstanding design, world class manufacturing and an extensive testing process that is performed on all products.
    • Richmond performance gearsets have been winners for decades at: NHRA, NMRA, NMCA, Daytona 500, WISSOTA and U.S. Nationals.
    • Richmond Gear is a leading manufacturer of high performance ring and pinion gearsets and drivetrain components, backed by a two year warranty.
    • Engineered to perform faster and be more reliable, Richmond performance drivetrain products are the result of a continuous research and development program combined with state-of-the-art manufacturing capabilities.
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    Yukon Gear – Bearing Race Driver (Part No.56016)

    Bearing Race Driver

    from

    $188.99
    Bearing race driver. No return.

    Product Features:
    • Bearing race driver
    • Fits HM89210 race
    • All steel construction
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    Yukon Gear – Redline Synthetic "Shock Proof" Oil With Positraction Additive – 4 Quarts (Part No.15005)

    Redline Synthetic "Shock Proof" Oil With Positraction Additive - 4 Quarts

    from

    $148.99
    Redline Synthetic “Shock Proof” Oil with positraction Additive. 4 Quarts.

    Product Features:
    • Includes four quarts of Redline Shockproof oil and one 4oz bottle of Yukon positraction additive
    See More

    Yukon Gear – Posi Spring Kit For GM 7.5", With Preload Plates (Part No.33206)

    Posi Spring Kit For GM 7.5", With Preload Plates

    from

    $153.99
    Product Features:
    • Positraction spring kit
    • Fits GM 7.5″ and 7.625″ Dura Grip
    • Includes preload plates
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    Yukon Gear – Set Up Bearing (Part No.56045)

    Set Up Bearing

    from

    $153.99
    M802048 set-up bearing (one bearing). No return.

    Product Features:
    • Set up bearing
    • Fits M802048 pinion bearing
    • Easily slips on and off pinion journal to allow for easier pinion depth adjustment
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    Yukon Gear – Positraction Clutch Guide (Part No.33352)

    Positraction Clutch Guide

    from

    $8.99
    Positraction clutch guide.

    Product Features:
    • Clutch guide for Chrysler 9.25″, Dana Spicer 44, Dana Spicer 50, Ford 8.8″, GM 12 bolt passenger car, GM 8.2″, 8.5″ and 8.6″, 1963-1979 Corvette and Nissan Titan
    • Compatible with Dura Grip positractions only
    See More

    Motive Gear – Differential Pinion Shim Kit (Part No.1104)

    Differential Pinion Shim Kit

    from

    $12.99


    Product Features:
    • KIT SHIM
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    Mr. Gasket – Differential Gasket (Part No.84)

    Differential Gasket

    from

    $24.99
    Mr. Gasket Axle Housing/Differential Cover or Rear End Gaskets are manufactured from a .047 inch thick cellulose/nitrile composite gasket material for excellent sealing and durability. They are precision die-cut for an excellent fit. Fits 1965-1970 Buick, Olds, Pontiac, 10 bolt 8.20 inch ring gear.

    Product Features:
    • .047″ thick cellulose/nitrile composite gasket material
    • Precision die cut
    • Reusable
    See More

    Yukon Gear – Standard Open Side Gear And Thrust Washer For GM 12 Bolt Car And Truck (Part No.33380)

    Standard Open Side Gear And Thrust Washer For GM 12 Bolt Car And Truck

    from

    $7.99
    Standard Open side gear thrust washer for 12P and 12T GM.

    Product Features:
    • Side gear thust washer for GM 12 bolt passenger car and truck
    • Fits standard open differentials only
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    Most Popular Rear Housing Cover Gasket for 1978 Pontiac Firebirds

    Enhance your 1978 Pontiac Firebird with this popular Rear Housing Cover Gasket we have in stock, for $10.99.

    Felpro – Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket (Part No.RDS 55028-1)

    Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket

    from

    $10.99
    Fel-Pro® gaskets are specifically designed for the repair environment to deliver a reliable seal on even the most troublesome applications. Designed for imperfect sealing surfaces and manufactured with proprietary materials, you can count on Fel-Pro for innovative sealing solutions for the real-world repair environment.

    Product Features:
    • Meets or exceeds all original equipment specifications
    • Application specific design to ensure a perfect fit
    • Unsurpassed quality you can trust
    • Validated for fit, form and function
    • Each Fel-Pro gasket, no matter how small, is engineered to exacting standards with proprietary design, engineering and manufacturing processes
    See More

    Best-Selling 1978 Pontiac Firebird Differential Oil

    Upgrade your Firebird with one of our 5 best-selling Differential Oil, earning an average 5 stars rating across 2 reviews.

    Valvoline – DEXRON – VI ATF Full Synthetic Automatic Transmission Fluid, 1 Quart (Part No.822405)

    DEXRON - VI ATF Full Synthetic Automatic Transmission Fluid, 1 Quart

    from

    $14.49
    Valvoline DEXRON-VI/MERCON LV ATF is a full-synthetic transmission fluid formulated with advanced additive technology to meet and exceed the requirements of the General Motors DEXRON-VI specification. It is officially licensed and approved by GM and is fully back-serviceable and can be used wherever DEXRON-II and/or DEXRON-III are recommended. Recommended for use in the following applications: DEXRON-VI, DEXRON-III, DEXRON-II, and Allison C-4.

    Product Features:
    • Formulated with full-synthetic base stocks and advanced additive technology to meet the challenging demands of automatic transmissions
    • Enhanced anti-shudder protection for smooth shifting and maximum power transfer
    • Developed with anti-wear technology to help improve transmission durability
    • Engineered with a proprietary blend of base oils and advanced additives to provide better oil flow at low temperatures and greater film protection at higher temperatures
    See More

    Valvoline – DEX/MERC ATF Conventional Automatic Transmission Fluid, 1 Quart (Part No.798153)

    DEX/MERC ATF Conventional Automatic Transmission Fluid, 1 Quart

    from

    $11.99
    Valvoline DEX/MERC ATF is a high-quality transmission fluid formulated to meet the challenging demands of many automatic transmissions. Its responsive low-temperature fluidity is beneficial in both electronic and hydraulic controlled transmissions and transaxles. Recommended for use in the following applications: MERCON*, DEXRON*-III, Ford M2C138-CJ and M2C166-H, Allison C-4 and TES-389, and Caterpillar TO-2.

    Product Features:
    • Formulated with premium base stocks and advanced additive technology to meet the challenging demands of automatic transmissions
    • Enhanced anti-shudder protection for smooth shifting and maximum power transfer
    • Developed with anti-wear technology to help improve transmission durability
    • Engineered with a proprietary blend of base oils and advanced additives to provide better oil flow at low temperatures and greater film protection at higher temperatures
    See More

    Yukon Gear – Redline Synthetic "Shock Proof" Oil With Positraction Additive – 4 Quarts (Part No.15005)

    Redline Synthetic "Shock Proof" Oil With Positraction Additive - 4 Quarts

    from

    $148.99
    Redline Synthetic “Shock Proof” Oil with positraction Additive. 4 Quarts.

    Product Features:
    • Includes four quarts of Redline Shockproof oil and one 4oz bottle of Yukon positraction additive
    See More

    Yukon Gear – Redline Synthetic "Shock Proof" Oil – 3 Quarts (Part No.15000)

    Redline Synthetic "Shock Proof" Oil - 3 Quarts

    from

    $99.99
    Redline Synthetic “Shock Proof” Oil. 3 Quarts.

    Product Features:
    • Includes three quarts of Redline Shockproof oil
    See More

    Yukon Gear – Redline Synthetic "Shock Proof" Oil – 4 Quarts (Part No.15004)

    Redline Synthetic "Shock Proof" Oil - 4 Quarts

    from

    $137.99
    Redline Synthetic “Shock Proof” Oil. 4 Quarts.

    Product Features:
    • Includes four quarts of Redline Shockproof oil
    See More

    Top-Quality Differential Bearings for 1978 Pontiac Firebirds

    Choose a high-quality OEM or aftermarket Differential Bearing for Pontiac Firebirds and enjoy top-notch performance from $4.49.

    National – Bearing Race (Part No.LM501314)

    Bearing Race

    from

    $9.29
    Manufactured with premium-grade steel, National taper bearing cups feature crowned raceways to ensure even load distribution.

    Product Features:
    • PREMIUM MATERIALS – Precision manufactured using premium-grade steel for outstanding durability and performance
    • SMOOTH ROTATION – Crowned raceways for even load distribution
    • OE-STYLE DESIGN – Engineered to meet OE specifications
    • COMPREHENSIVE COVERAGE – Industry-leading coverage for domestic and import applications
    • RIGOROUS TESTING – Comprehensive testing throughout design and development processes by National engineers for quality you can count on
    See More

    National – Tapered Roller Bearing Cone (Part No.LM501349)

    Tapered Roller Bearing Cone

    from

    $19.99
    Manufactured with premium-grade steel, National taper bearing cones feature crowned raceways and rollers to ensure even load distribution.

    Product Features:
    • PREMIUM MATERIALS – Precision manufactured using premium-grade steel for outstanding durability and performance
    • SMOOTH ROTATION – Crowned raceways and rollers for even load distribution
    • OE-STYLE DESIGN – Engineered to meet OE specifications
    • COMPREHENSIVE COVERAGE – Industry-leading coverage for domestic and import applications
    • RIGOROUS TESTING – Comprehensive testing throughout design and development processes by National engineers for quality you can count on
    See More

    National – Bearing Race (Part No.LM67010)

    Bearing Race

    from

    $4.49
    National Oil Seals & Bearings offer a full line of premium oil seals and bearings.

    Product Features:
    • PREMIUM MATERIALS — Precision manufactured using premium-grade steel for outstanding durability and performance
    • SMOOTH ROTATION — Crowned raceways for even load distribution
    • OE-STYLE DESIGN — Engineered to meet OE specifications
    • COMPREHENSIVE COVERAGE — Industry-leading coverage for domestic and import applications
    • RIGOROUS TESTING — Comprehensive testing throughout design and development processes by National engineers for quality you can count on
    See More

    FAG US – Cone (Part No.KM86649)

    Cone

    from

    $24.29
    With advanced load-carrying capacity and compact design, tapered roller bearings are used in wheel bearings, transmissions, differentials, transfer cases and other miscellanous applications. FAG manufacturers over 100 million tapered roller bearings annually.

    Product Features:
    • High-precision and High-quality components used in all KITs
    • Coverage of classic and new high-tech solutions for the best system coverage
    See More

    FAG US – Cup (Part No.M88010)

    Cup

    from

    $11.29
    With advanced load-carrying capacity and compact design, tapered roller bearings are used in wheel bearings, transmissions, differentials, transfer cases and other miscellanous applications. FAG manufacturers over 100 million tapered roller bearings annually.

    Product Features:
    • High-precision and High-quality components used in all KITs
    • Coverage of classic and new high-tech solutions for the best system coverage
    See More

    Yukon Gear – Cross Pin Bolt (Part No.33067)

    Cross Pin Bolt

    from

    $6.99
    Cross pin bolt for Chrysler 8.25″, 9.25″ rear, Ford 7.5″, 8.8″, GM 12 bolt car & truck, 7.2″ IFs, 7.5″, 7.6″, 8.0″, 8.25″ IFS & 8.5″.

    Product Features:
    • Cross pin bolt for Chrysler 8.25″ and 9.25″ rear, Ford 7.5″ and 8.8″, GM 12 botl car and truck, 8.5″, 8.25″ IFS, 8.0″, 7.625″, 7.5″ and 7.2″ IFS
    See More

    FAG US – Cup (Part No.LM67010)

    Cup

    from

    $6.69
    With advanced load-carrying capacity and compact design, tapered roller bearings are used in wheel bearings, transmissions, differentials, transfer cases and other miscellanous applications. FAG manufacturers over 100 million tapered roller bearings annually.

    Product Features:
    • High-precision and High-quality components used in all KITs
    • Coverage of classic and new high-tech solutions for the best system coverage
    See More

    Top Picks for 1978 Pontiac Firebird Rear Differential Cover Gaskets

    Invest in one of our 4 durable Rear Differential Cover Gaskets for your 1978 Pontiac, knowing you’re getting trusted brands and expert craftsmanship.

    Mr. Gasket – Differential Gasket (Part No.84B)

    Differential Gasket

    from

    $20.99
    Mr. Gasket Axle Housing/Differential Cover or Rear End Gaskets are manufactured from a .047 inch thick cellulose/nitrile composite gasket material for excellent sealing and durability. They are precision die-cut for an excellent fit. Fits 1964-1970 Chevrolet 8.2 inch 10 bolt & 1970-1981 GM 8.5 inch ring gear

    Product Features:
    • .047″ thick cellulose/nitrile composite gasket material
    • Precision die cut
    • Reusable
    See More

    Yukon Gear – 7.5 GM Cover Gasket (Part No.23018)

    7.5 GM Cover Gasket

    from

    $11.99
    7.5 GM cover gasket.

    Product Features:
    • Cover gasket
    • Fits GM 7.5″ and 7.625″
    See More

    Pro-King – Differential Cover Gasket (Part No.742G303A)

    Differential Cover Gasket

    from

    $31.49
    Pro-King is the leading supplier of transmission and driveline products in the aftermarket.

    Product Features:
    • All products are designed to meet or exceed OE quality, form, fit and funtion.
    See More

    Yukon Gear – 8.2" & 8.5" Rear Cover Gasket (Part No.23020)

    8.2" & 8.5" Rear Cover Gasket

    from

    $10.99
    8.2″ & 8.5″ rear cover gasket.

    Product Features:
    • Cover gasket
    • Fits GM 8.2″, 8.5″ and 8.6″
    See More

    Top-Rated Differential Covers for 1978 Pontiac Firebirds

    Make a smart move for your 1978 Pontiac Firebird with products all priced from $67.99 to $379.99.

    Mr. Gasket – Differential Cover Kit (Part No.9891)

    Differential Cover Kit

    from

    $75.99
    Add some bling to the underside of your car with Mr. Gasket’s chrome differential cover. This chrome-plated steel cover is made to fit GM 10-bolt with 8 1/2 in ring gear. Is a complete kit with a gasket and bolts.

    Product Features:
    • Made Of Chrome Plated Steel
    • Fits GM 8.5-Inch 10 Bolt
    • Complete Kit With Gasket And Bolts
    See More

    Yukon Gear – Chrome Cover For 8.6", 8.5" And 8.2" GM Rear (Part No.32017)

    Chrome Cover For 8.6", 8.5" And 8.2" GM Rear

    from

    $74.99
    Chrome cover for 8.6″, 8.5″ and 8.2″ GM rear.

    Product Features:
    • Fits GM 8.2″, 8.5″ and 8.6″
    • Chrome
    See More

    Yukon Gear – Aluminum Girdle Cover For GM 7.5" & 7.625" (Part No.32118)

    Aluminum Girdle Cover For GM 7.5" & 7.625"

    from

    $379.99
    Product Features:
    • Fits GM 7.5″ and 7.625″
    • Aluminum girdle cover
    See More

    Yukon Gear – Polished Aluminum Cover For 8.6", 8.2" And 8.5" GM Rear (Part No.32030)

    Polished Aluminum Cover For 8.6", 8.2" And 8.5" GM Rear

    from

    $255.99
    Polished aluminum cover for 8.6″, 8.2″ and 8.5″ GM rear.

    Product Features:
    • Fits GM 8.5″ and 8.6″
    • Finned polished aluminum
    See More

    Yukon Gear – Steel Cover For GM 8.2" & 8.5" Rear (Part No.32332)

    Steel Cover For GM 8.2" & 8.5" Rear

    from

    $123.99
    Product Features:
    • Fits GM 8.2″, 8.5″ and 8.6″
    • Steel
    See More

    Yukon Gear – Steel Cover For GM 7.5" & 7.625" (Part No.32331)

    Steel Cover For GM 7.5" & 7.625"

    from

    $67.99
    Product Features:
    • Fits GM 7.5″ and 7.625″
    • Steel
    See More

    Yukon Gear – Chrome Cover For 7.5" GM (Part No.32014)

    Chrome Cover For 7.5" GM

    from

    $67.99
    Chrome cover for 7.5″ GM.

    Product Features:
    • Fits GM 7.5″ and 7.625″
    • Chrome
    See More

    Top-Rated Differential Brands For Your 1978 Pontiac Firebird

    When it comes to finding the perfect Differential for your 1978 Pontiac Firebird, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 14 trusted brands. We carry the most popular Differential brands including National, DriveWorks, and Motive Gear, and more, all known for their exceptional customer ratings (average brand rating of 4.3 stars) and competitive prices, as low as $7.99. Purchasing a Differential from us here at Advance Auto Parts is a smart move for both you and your 1978 Pontiac Firebird, providing peace of mind with parts that meet or exceed OEM standards.

    Popular National 1978 Pontiac Firebird Differentials

    If you’re looking for a top-quality Differential for your 1978 Pontiac Firebird, Advance Auto Parts has exactly what you need with our selection of National Differentials. We have 3 National Differentials in stock for this fitment, all known for their durability and precision fit. With prices starting at just $7.99 and an average cost of $18.42, you’ll find the perfect Differential for your needs and budget. National Differentials for the 1978 Pontiac Firebird come highly rated, with over 7 customer reviews and an impressive average rating of 4.3 stars. Choosing a National Differential from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.
    Shaft Repair Sleeve
    from $37.99
    (1)
    Shaft Repair Sleeve
    “Very delicate piece, but came shipped quite safely and not damaged. High quality.”
    Bearing Race
    from $9.29
    (2)
    Bearing Race
    “Reasonable price and woks well. front diff 2006 Escalade esv”
    Bearing Race
    from $7.99
    (4)
    Bearing Race
    “Goes with M88010 bearing cup. Application was the pinion bearing race for a Ford 9 Inch on a 1957 Ford F-100.”

    Top-Quality DriveWorks 1978 Pontiac Firebird Differentials

    For those in search of a high-quality Differential for their 1978 Pontiac Firebird, Advance Auto Parts offers a great selection of DriveWorks Differentials. With 1 DriveWorks Differentials in stock, you can trust you’re getting top-tier parts designed for durability and a perfect fit. Prices for these Differentials start at just $7.99, giving you a range of options to suit your budget. Backed by over 1 customer ratings and an average rating of 4.3 stars, DriveWorks Differentials provide both reliability and excellent performance. Choosing a DriveWorks Differential from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
    Oil Seal
    from $7.99
    (1)
    Oil Seal
    “Didn’t fit my 1992 K1500 10 bolt 8.5″ ring gear rear end. Was told wrong part.”

    FAQs for 1978 Pontiac Firebird Differentials

    What are the best-selling Differentials for 1978 Pontiac Firebirds?

    Out of 267 Differentials that fit 1978 Pontiac Firebirds, the following parts are the top sellers:

    What’s the price range for 1978 Pontiac Firebird Differentials?

    The prices of Differentials for the 1978 Pontiac Firebird range from $2.59 up to $1,153.99 for the most premium parts.

    What is the average price of a Differential for a 1978 Pontiac Firebird?

    The average price for Differentials for the 1978 Pontiac Firebird is $212.72. Keep in mind the variety of part types within our Differential category, where you are likely to find a wide range of prices across a variety of parts and components.

    Does Advance Auto Parts sell Differentials for other Pontiac Firebird model years?

    Yes, we carry Differentials for 34 model years of Pontiac Firebirds between 1967 and 2002. The following model years are the most popular for Differential purchases: 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995, and 1994.

    What are the cheapest Differentials for my 1978 Pontiac Firebird?

    The cheapest 1978 Pontiac Firebird Differentials we carry are:

    Does Advance Auto Parts sell Differentials for any other 1978 Pontiac models?

    Yes. We stock Differentials for 8 other popular 1978 Pontiac models. Some of the most popular are 1978 Grand Prix Differentials, 1978 Bonneville Differentials, 1978 Grand Am Differentials, 1978 LeMans Differentials, and 1978 Catalina Differentials.

    What are the top-rated Differentials that fit the 1978 Pontiac Firebird?

    The one 1978 Pontiac Firebird Differential we have in stock is the Differential Pinion Gear Washer. It costs $2.59.

    What types of Differentials do you sell for my 1978 Pontiac Firebird?

    As of 11/2/25, these are some of the most in-demand types of Differentials for a 1978 Pontiac Firebird:

    Can I get help with 1978 Pontiac Firebird Differential orders?

    Contact our customer support team by chat or phone, through the help desk page, where you can find instant answers about Pontiac Differentials and more.

    What is your return policy for Pontiac Firebird Differentials?

    Advance Auto Parts keeps returns simple. For new Pontiac Firebird Differentials and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.