1985 Pontiac Firebird Differentials

Keep Your 1985 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 1985 Pontiac Firebird looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Differential Bearings, Differential Pinion Seals, and Differential Oil. 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, Dorman, and Motive Gear. For example, National Differentials start at just $7.79 with an average 4.3 star rating. Dorman and Motive Gear offer similar pricing and quality, backed by strong customer feedback. With over 1,200 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 1985 Pontiac Firebird Differential at Advance Auto Parts is around $287.19, with a range that starts at $2.79 and goes up to $2,219.99. With 172 options in stock from 15 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 1985 Pontiac Firebird in peak condition, inside and out.

Essential 1985 Pontiac Firebird Differentials

Yukon Gear – Pinion Nut (Part No.33150)

Pinion Nut

from

$11.99
Pinion nut for GM 12 bolt car & truck, 55-62 car & truck, 8.2″, 8.2″ Buick/Olds/Pontiac & 63-79 Corvette. 1 1/8″ socket, 7/8″ x 16 thread.

Product Features:
  • Pinion nut for GM 12 bolt car and truck, 8.2″, 8.2″ Buick, Oldsmobile and Pontiac and 1963-1979 Corvette
  • 7/8″ x 16 thread
  • 1 1/8″ socket
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Yukon Gear – Dura Grip Case, GM 12 Bolt Car, 4 Series (Part No.20105)

Dura Grip Case, GM 12 Bolt Car, 4 Series

from

$399.99
GM 12P DURA GRIP case, bare, 4.10 & up, 30spline & 33spline.

Product Features:
  • Fits GM 12 bolt passenger car with 33 spline axles
  • Does not include spider gears
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Powertrax – Lock Right Locker (Part No.1930-LR)

Lock Right Locker

from

$445.99
The Powertrax Lock-Right ultra-strength alloy locker’s straight-line performance is equal to a solid spool, but automatically unlocks in turns. Best suited for extreme off-road to severe on-road use, Powertrax Lock Right lockers replace the spider gears in your open differential carrier using basic tools and without affecting your ring and pinion settings. The whole job can be done in your driveway in a couple of hours, pin included! 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 – 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
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    Richmond Gear – RngPnn (Part No.49-0095-1)

    RngPnn

    from

    $389.99
    RngPnn

    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

    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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    National – Shaft Repair Sleeve (Part No.99199)

    Shaft Repair Sleeve

    from

    $37.99
    National has built a reputation as one of the most respected names in the industry. We have offered premium sealing solutions for more than 75 years. Our design team keeps pace with the industry and provides advanced solutions for today’s vehicles.

    Product Features:
    • Designed to repair damaged, grooved or worn shafts
    • Durable stainless steel construction for corrosion-free sealing surface that surpasses most original shaft specifications
    • Ideal for a shaft where indications of seal wear, such as tracks or grooves have developed
    • Ultra-thin construction (0.01/0.25mm wall thickness) allows original seal size to be used with minimal additional lip loading
    • Easy to install with removable flange and installation tool
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    Dorman – Rear Axle Shaft, Left Or Right (Part No.630-150A)

    Rear Axle Shaft, Left Or Right

    from

    $146.99
    Axle shaft damaged or bearings worn out: This axle shaft directly replaces the original equipment on certain vehicles, complete with all necessary application-specific installation components.

    Product Features:


      Product Features:
      • Direct replacement – this axle shaft replaces the original equipment on specific vehicle years, makes and models
      • Complete kit – each shaft includes critical installation hardware and components needed for specific vehicle applications
      • Durable construction – designed to rigorous standards and tested to ensure performance
      • Trustworthy solution – backed by team of engineers and quality control specialists in the United States
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    Yukon Gear – Steel Spool For GM 12 Bolt Car With 30 Spline Axles, 4.10 & Up (Part No.32187)

    Steel Spool For GM 12 Bolt Car With 30 Spline Axles, 4.10 & Up

    from

    $379.99
    Yukon Performance 2-1/16″ deck steel spool for GM 12P with 30 spline axles. Spool uses 1.785″ journal bearings. fits 4.10 and up. Yukon performance spools are made from the highest quality materials to ensure high strength and long life in performance applications. Spools provide 100% power to both tires at all times and are a lower cost alternative to lockers. Spools are not recommended for street driven vehicles. Yukon Performance spools come with a one year warranty against manufacturing defects. This spool requires the use of a C-Clip eliminator kit to be used.

    Product Features:
    • Fits GM 12 bolt passenger car with 30 spline axles
    • 4.10 and up ratio only
    • Provides 100% traction to both wheels at all times
    • Not recommended for street driven vehicles
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    National – Bearing Race (Part No.HM89410)

    Bearing Race

    from

    $10.79
    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

    Yukon Gear – Positraction Internals For GM 12 Bolt Car And Truck With 33 Spline Axles (Part No.16040)

    Positraction Internals For GM 12 Bolt Car And Truck With 33 Spline Axles

    from

    $305.99
    Yukon positraction internals for GM 12P and 12T with 33 spline axles. Yukon uses higher quality materials and better techniques than OEM to ensure a longer lasting spider gear set. This kit does not include clutches. All components come with a one year warranty against manufacturing defects.

    Product Features:
    • Spider gear kit
    • Fits GM 12 bolt passenger car with 33 spline Dura Grip positraction
    • Includes two side gears, two pinion gears, cross pin shaft, roll pin and spider gear thrust washers.
    See More

    Powertrax – No-Slip Traction System (Part No.9207853005)

    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 – Bearing Race Driver (Part No.56022)

    Bearing Race Driver

    from

    $188.99
    Bearing race driver. No return.

    Product Features:
    • Bearing race driver
    • Fits M86610 race
    • All steel construction
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    Richmond Gear – MiniSpool (Part No.78-1230-1)

    MiniSpool

    from

    $151.99
    MiniSpool

    Felpro – Axle Housing Cover Gasket Oval Shaped 12 Bolt Hole Gasket (Part No.RDS 55029)

    Axle Housing Cover Gasket Oval Shaped 12 Bolt Hole Gasket

    from

    $8.49
    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
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    Yukon Gear – Differential Cover B (Part No.33572)

    Differential Cover B

    from

    $7.99
    Differential Cover B

    Yukon Gear – Pinion Depth Shims For GM 8.25" IFS, 8.5", 12 Bolt Car, Ford 8.8" & Chrysler 8.25" (Part No.55009)

    Pinion Depth Shims For GM 8.25" IFS, 8.5", 12 Bolt Car, Ford 8.8" & Chrysler 8.25"

    from

    $27.99
    8.25″ IFS, 8.5″, 12P, 7.5″ F, 8.8″ F, 8.25″ Chrysler pinion shim kit.

    Product Features:
    • Pinion depth shims for GM 8.25″ IFS, 8.5″, 8.6″, 12 bolt passenger car, Ford 7.5″ and 8.8″, Chrysler 8.25″
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    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 – 8.6" GM 12P 12T & F8.8 Carrier Installation Kit (Part No.57010)

    8.6" GM 12P 12T & F8.8 Carrier Installation Kit

    from

    $121.99
    Yukon Carrier installation kits are great, low cost kit for carrier changes such as Positraction or locker upgrades. Carrier installation kit for GM 8.6″, 12 bolt car and 12 bolt truck differential. This kit contains carrier bearings, races and shims.

    Product Features:
    • Fits GM 12 bolt passenger car and truck and 8.6″
    • Includes carrier bearings and races and “super” carrier shim kit
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    Spectre – W3 Diff Cover 10 Bolt (Part No.60703)

    W3 Diff Cover 10 Bolt

    from

    $39.99
    Spectre Differential Covers are made to OEM specifications and are triple chrome plated for a lasting shine. Designed to protect the intricate moving parts of the differential, Spectre’s covers add an extra layer of protection to the vehicle’s underside. Featuring a 10-bolt design and including the necessary chrome bolts and gaskets, this differential cover is designed to fit 1964-1972 Chevy/GM intermediates, 1983-1987 Chevy/GMC 1/2 Ton two or four wheel drive rear, and 1967-1972 Chevy Camaros. Includes 10 SAE standard chrome bolts for installation. You’ll need to supply your own bolts if your application requires metric bolts.

    Product Features:
    • Made exactly to OEM specifications
    • 10-bolt design, includes chrome bolts and gasket
    • Triple chrome plated for a lasting shine
    • 10 chrome 5/16 inch -18 x 3/4 inch differential cover bolts included
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    Powertrax – Grip LS Traction System (Part No.LS201028)

    Grip LS Traction System

    from

    $463.99
    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!
    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 – Pinion Install Kit For GM 12 Bolt Car Differential (Part No.13056)

    Pinion Install Kit For GM 12 Bolt Car Differential

    from

    $232.99
    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 GM 12 bolt passenger car
    • Included are pinion bearings and races, pinion seal, crush sleeve, complete pinion shim kit, and marking compound with brush.
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    USA Standard Gear – Master Overhaul Kit for the 8.2" Buick, Olds, Pontiac Differential (Part No.37054)

    Master Overhaul Kit for the 8.2" Buick, Olds, Pontiac Differential

    from

    $279.99
    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 8.2″ Buick, Oldsmobile and Pontiac
    • 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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    Yukon Gear – Posi Shim Kit For GM 7.5" & 7.625" Eaton Positraction (Part No.16047)

    Posi Shim Kit For GM 7.5" & 7.625" Eaton Positraction

    from

    $42.99
    Product Features:
    • Shim kit
    • Fits GM 7.5″ and 7.625″ with Eaton positraction
    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.
    See More

    Yukon Gear – Crush Sleeve Eliminator Kit For GM 7.5" & 8.2" (Part No.55047)

    Crush Sleeve Eliminator Kit For GM 7.5" & 8.2"

    from

    $40.99
    Product Features:
    • Crush sleeve eliminator kit for GM 7.5″, 7.625″ and 8.2″
    See More

    Most Popular Differential Bearings for 1985 Pontiac Firebirds

    Enhance your 1985 Pontiac Firebird with one of the 8 Differential Bearings we have in stock, starting at just $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 – Bearing Race (Part No.LM102910)

    Bearing Race

    from

    $7.79
    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 – Bearing – TRB (Tapered Roller Bearing) (Part No.KT5)

    Bearing - TRB (Tapered Roller Bearing)

    from

    $21.29
    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

    Best-Selling 1985 Pontiac Firebird Differential Pinion Seals

    Upgrade your Firebird with one of our 4 best-selling Differential Pinion Seals.

    Motive Gear – Pinion Seal (Part No.8610)

    Pinion Seal

    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.
    See More

    Yukon Gear – 7.2" GM 7.5" GM & 8.2" GM Pinion Seal (Part No.30192)

    7.2" GM 7.5" GM & 8.2" GM Pinion Seal

    from

    $9.99
    7.2″ GM 7.5″ GM & 8.2″ GM pinion seal.Yukon Mighty seal.

    Product Features:
    • Pinion seal
    • Fits GM 7.2″ IFS, 1999 and down GM 7.5″ and 7.625″ and GM 8.2″
    • 2.660″ O.D.
    See More

    Yukon Gear – 7.75" Pinion Seal (Part No.30269)

    7.75" Pinion Seal

    from

    $22.99
    7.75″ pinion seal.Yukon Mighty seal.

    Product Features:
    • Pinion seal
    • Fits GM 7.75″
    See More

    National – Multi-Purpose Seal (Part No.224255)

    Multi-Purpose Seal

    from

    $9.99
    National® has built a reputation as one of the most respected names in the industry. We have offered premium sealing solutions for more than 75 years. Our design team keeps pace with the industry and provides advanced solutions for today’s vehicles.

    Product Features:
    • Design type: spring loaded; multi-lip
    • Temperature range: -20 Deg. F to 300 Deg. F / -29 Deg. C to 49 Deg. C
    • Resistance to EP lubricants
    • Low swell in hydrocarbon fluids
    • Delivers quality and reliable performance for every type of repair
    See More

    Top-Quality Differential Oil for 1985 Pontiac Firebirds

    Choose a high-quality OEM or aftermarket Differential Oil for Pontiac Firebirds and enjoy top-notch performance from $11.99.

    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
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    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
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    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
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    Top Picks for 1985 Pontiac Firebird Rear Differential Cover Gaskets

    Invest in one of our 2 durable Rear Differential Cover Gaskets for your 1985 Pontiac, knowing you’re getting trusted brands and expert craftsmanship.

    Felpro – Axle Housing Cover Gasket Irregular Shaped 10 Bolt Hole Gasket (Part No.RDS 55072)

    Axle Housing Cover Gasket Irregular Shaped 10 Bolt Hole Gasket

    from

    $8.99
    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
    • Engineered for the sealing repair environment
    • Validated for fit, form and function
    • Unsurpassed quality you can trust
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    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″
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    Top-Rated Differential Covers for 1985 Pontiac Firebirds

    Make a smart move for your 1985 Pontiac Firebird with products all priced from $24.99 to $379.99.

    Dorman – Differential Cover (Part No.697-701)

    Differential Cover

    from

    $24.99
    This direct replacement differential cover matches the fit and function of the original equipment diff cover for a reliable, leak-free repair. It features a durable design, made to strict specifications, to help ensure reliable service life.

    Product Features:
    • Direct replacement – this differential cover matches the fit and function of the original equipment diff cover on select vehicles
    • Reliable repair – the smart solution for fixing an existing cover that’s rusted, damaged or leaking differential fluid
    • Durable construction – this differential cover is made according to strict engineering standards to help ensure dependability
    • Trustworthy quality – backed by a team of product experts in the United States and more than a century of automotive experience
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    ATP – DIFF COVER KIT (Part No.111102)

    DIFF COVER KIT

    from

    $29.99
    DIFF COVER KIT

    Mr. Gasket – Differential Cover Kit (Part No.9896)

    Differential Cover Kit

    from

    $74.99
    The Mr. Gasket chrome plated rear end cover is made from heavy-gauge steel and comes complete with bolts and gaskets.

    Product Features:
    • Chrome plated steel for looks
    • Includes bolts and gasket
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    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
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    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
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    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

    Pro-King – Differential Carrier Cover (Part No.741A758)

    Differential Carrier Cover

    from

    $29.99
    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

    Top-Rated Differential Brands For Your 1985 Pontiac Firebird

    When it comes to finding the perfect Differential for your 1985 Pontiac Firebird, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 15 trusted brands. We carry the most popular Differential brands including National, Dorman, 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 $6.79. Purchasing a Differential from us here at Advance Auto Parts is a smart move for both you and your 1985 Pontiac Firebird, providing peace of mind with parts that meet or exceed OEM standards.

    Popular National 1985 Pontiac Firebird Differentials

    If you’re looking for a top-quality Differential for your 1985 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 $7.79 and an average cost of $56.36, you’ll find the perfect Differential for your needs and budget. National Differentials for the 1985 Pontiac Firebird come highly rated, with over 10 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.
    Bearing Race
    from $9.29
    (2)
    Bearing Race
    “Reasonable price and woks well. front diff 2006 Escalade esv”
    Bearing Race
    from $7.79
    (6)
    Bearing Race
    “perfect fit”
    Axle Differential Bearing & Seal Kit
    from $151.99
    (2)
    Axle Differential Bearing & Seal Kit
    “All you need to overhaul a diff, at a good price”

    Top-Quality Dorman 1985 Pontiac Firebird Differentials

    For those in search of a high-quality Differential for their 1985 Pontiac Firebird, Advance Auto Parts offers a great selection of Dorman Differentials. With 2 Dorman 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 $6.79, with an average price of $15.89, giving you a range of options to suit your budget. Backed by over 49 customer ratings and an average rating of 4.2 stars, Dorman Differentials provide both reliability and excellent performance. Choosing a Dorman Differential from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
    Differential Cover
    from $24.99
    (38)
    Differential Cover
    “Looks great, face lift for the rear differential. Old one was rusted & in bad shape. Just remember to get the correct size.”
    Differential Shaft Lock Bolt
    from $6.79
    (11)
    Differential Shaft Lock Bolt
    “Exactly like OEM”

    FAQs for 1985 Pontiac Firebird Differentials

    What are the best-selling Differentials for 1985 Pontiac Firebirds?

    Out of 172 Differentials that fit 1985 Pontiac Firebirds, the following parts are the top sellers:

    What’s the price range for 1985 Pontiac Firebird Differentials?

    The prices of Differentials for the 1985 Pontiac Firebird range from $2.79 up to $2,219.99 for the most premium parts.

    What is the average price of a Differential for a 1985 Pontiac Firebird?

    The average price for Differentials for the 1985 Pontiac Firebird is $287.19. 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 1985 Pontiac Firebird?

    The cheapest 1985 Pontiac Firebird Differentials we carry are:

    Does Advance Auto Parts sell Differentials for any other 1985 Pontiac models?

    Yes. We stock Differentials for 6 other popular 1985 Pontiac models. Some of the most popular are 1985 Grand Prix Differentials, 1985 Bonneville Differentials, 1985 Grand Am Differentials, 1985 Sunbird Differentials, and 1985 Parisienne Differentials.

    What types of Differentials do you sell for my 1985 Pontiac Firebird?

    As of 11/2/25, these are some of the most in-demand types of Differentials for a 1985 Pontiac Firebird:

    Can I get help with 1985 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.