1978 GMC G15 Differentials

Keep Your 1978 GMC G15 in Top Shape with Quality Differentials

Whether you’re repairing or upgrading your Differential, using high-quality parts is key to keeping your 1978 GMC G15 looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Differential Oil, Differential Covers, and Rear Housing Cover Gaskets. 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 1,824 reviews and a solid 4 star average, you can shop with confidence knowing other GMC G15 owners approve.

Competitive Prices and Extensive Inventory

The average price for a 1978 GMC G15 Differential at Advance Auto Parts is around $256.45, with a range that starts at $2.59 and goes up to $1,969.99. With 196 options in stock from 13 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 Multi-Purpose Bearing start at just $11.99 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 GMC G15 in peak condition, inside and out.

Essential 1978 GMC G15 Differentials

Richmond Gear – MiniSpool (Part No.78-1230-1)

MiniSpool

from

$151.99
MiniSpool

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
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Yukon Gear – Pinion Install Kit For GM 12 Bolt Truck Differential (Part No.13057)

Pinion Install Kit For GM 12 Bolt Truck 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, pinion nut, 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 truck
  • Included are pinion bearings and races, pinion seal, crush sleeve, complete pinion shim kit, and marking compound with brush.
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Richmond Gear – RngPnnInstlKt (Part No.83-1018-B)

RngPnnInstlKt

from

$39.49
RngPnnInstlKt

National – Multi-Purpose Bearing (Part No.A-36)

Multi-Purpose Bearing

from

$27.99
Product Features:
  • CONSISTENT PERFORMANCE: Matched cup and cone components ensure consistent performance
  • 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
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Richmond Gear – Differential Cross Shaft (Part No.80-0269-1)

Differential Cross Shaft

from

$64.99
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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Pro-King – Differential Ring Gear Bolt (Part No.742G935)

Differential Ring Gear Bolt

from

$2.99
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.
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USA Standard Gear – Spartan Locker For GM 12 Bolt Car & Truck With 30 Spline Axles, Includes Heavy-Duty Cross Pin Shaft (Part No.17032)

Spartan Locker For GM 12 Bolt Car & Truck With 30 Spline Axles, Includes Heavy-Duty Cross Pin Shaft

from

$672.99
The Spartan Locker, by USA Standard Gear, provides reliable traction at a low cost. Give your vehicle great traction and save some cash. Choose a Spartan Locker for better traction. The Spartan locker by USA standard gear is a mechanical locker that replaces the spiders in a standard case. The Spartan locker’s design does not use the thrust washers and has a revolutionary spring and pin design that makes installation a snap! The couplers and drivers are made from 9310 steel, for added strength. Each Spartan locker carries a one year warranty against defect.

Product Features:
  • Fits GM 12 bolt car and truck with 30 spline axles
  • Made from 9310 steel for added strength
  • Replaces the spiders in a standard carrier case
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Yukon Gear – Positraction Shim Kit (18 Shims) For GM 8.2", GM 8.5", 12T, 12P, Ford 8.8" & Cast Iron ‘Vette (Part No.16042)

Positraction Shim Kit (18 Shims) For GM 8.2", GM 8.5", 12T, 12P, Ford 8.8" & Cast Iron 'Vette

from

$41.99
Product Features:
  • Shim 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
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Dorman – Differential Ring and Pinion Set (Part No.697-301)

Differential Ring and Pinion Set

from

$316.99
This differential ring and pinion directly replaces the original equipment on specific vehicle years, makes and models.

Product Features:
  • Direct replacement – this ring and pinion set matches the fit and function of the original components on certain vehicle applications
  • Effective fix – eliminates grinding and whining from failed original bearings
  • Thoroughly tested – vehicle try-on testing and rigorous quality control measures ensure longevity
  • Trustworthy quality – backed by team of designers and engineers in the United States
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Yukon Gear – Differential (Part No.26052)

Differential

from

$709.99
Differential

Yukon Gear – 18 Plate Steel Clutches For GM 8.2", GM 8.5", 12T, 12P, Ford 8.8" & Cast Iron ‘Vette (Part No.16110)

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

from

$483.99
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
  • 18 piece kit
  • Steel clutches
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Yukon Gear – Super Carrier Shim Kit For Ford 8.8", GM 12 Bolt Car & Truck, 8.6 & Vette (Part No.55002)

Super Carrier Shim Kit For Ford 8.8", GM 12 Bolt Car & Truck, 8.6 & Vette

from

$59.99
Product Features:
  • Super carrier shim kit for Ford 8.8″, GM 12 bolt passenger car and truck, GM 8.0″, 8.6″, 8.6″ IRS and 1963-1979 Corvette
  • Interlocking design makes installation much easier
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Powertrax – No-Slip Traction System (Part No.9207883005)

No-Slip Traction System

from

$551.99
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!
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    Dorman – Differential Pinion Yoke Assembly (Part No.697-553)

    Differential Pinion Yoke Assembly

    from

    $242.99
    Worn or damaged differential end yoke causing driveline vibrations? This direct replacement end yoke matches the original equipment part for a trustworthy repair and reliable performance.

    Product Features:
    • Direct replacement – this differential end yoke matches the fit and construction of the original yoke
    • Excellent value – this replacement end yoke offers original equipment quality at a fraction of the price of dealer parts
    • Quality materials – this end yoke is machined from cast iron for strength and is precision machined for reliability
    • Validated fit – this differential end yoke has been tested to confirm accurate fit
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    Motive Gear – Pinion Nut (Part No.3752901)

    Pinion Nut

    from

    $7.99
    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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    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
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    Driveworks – Oil Seal (Part No.S-2043)

    Oil Seal

    from

    $7.99
    Value-priced seal meets all cataloged application requirements.

    Product Features:
    • Brand may vary by location
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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
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    Powertrax – Grip LS Traction System (Part No.LS231230)

    Grip LS Traction System

    from

    $480.99
    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

    Pro-King – Differential Cross Shaft (Part No.742G673)

    Differential Cross Shaft

    from

    $28.49
    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.
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    USA Standard Gear – 12 Bolt GM Spartan Locker Cross Pin (Part No.17023)

    12 Bolt GM Spartan Locker Cross Pin

    from

    $49.99
    Product Features:
    • USA Standard Gear heavy-duty cross pin shaft
    • Fits GM 12 bolt car and truck and 9.5″ Toyota Landcruiser
    • Works with Spartan Locker or standard open spider gears
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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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    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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    Yukon Gear – Dana 25, 27, 30, 44, Model 20 And Model 35, GM 7.5", 8.2", 8.5", 12P, 12T, C9.25 Rear Cover Bolt (Part No.33286)

    Dana 25, 27, 30, 44, Model 20 And Model 35, GM 7.5", 8.2", 8.5", 12P, 12T, C9.25 Rear Cover Bolt

    from

    $9.99
    5/16″-18 cover bolt, Dana Spicer 25, 27, 30 and 44, AMC Model 20 and Model 35, Chrysler 9.25 rear, GM 7.5″, 7.625″, 8.2″, 8.5″, 12 bolt passenger car and truck.

    Product Features:
    • Cover bolt for Dana Spicer 25, 27, 30 and 44, AMC Model 20 and Model 35, GM 7.5″, 7.625″, 8.2″, 8.5″ and 12 bolt passenger car and truck.
    • 1/2″ head
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    National – Multi-Purpose Bearing (Part No.A-5)

    Multi-Purpose Bearing

    from

    $16.99
    Product Features:
    • CONSISTENT PERFORMANCE: Matched cup and cone components ensure consistent performance
    • 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

    Yukon Gear – Crush Sleeve Eliminator Kit For GM 12 Bolt Truck (Part No.55046)

    Crush Sleeve Eliminator Kit For GM 12 Bolt Truck

    from

    $47.99
    12T solid crush sleeve replacement spacer, pinion preload.

    Product Features:
    • Crush sleeve eliminator kit for GM 12 bolt truck
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    Pro-King – Differential Crush Sleeve (Part No.742G034)

    Differential Crush Sleeve

    from

    $2.99
    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

    Most Popular Differential Oil for 1978 GMC G15s

    Enhance your 1978 GMC G15 with one of the 5 Differential Oil we have in stock, starting at just $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
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    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

    Best-Selling 1978 GMC G15 Differential Covers

    Upgrade your G15 with one of our 2 best-selling Differential Covers.

    Yukon Gear – Chrome Cover For GM 12 Bolt Truck (Part No.32012)

    Chrome Cover For GM 12 Bolt Truck

    from

    $64.99
    Chrome cover for GM 12T.

    Product Features:
    • Fits GM 12 bolt truck
    • Chrome
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    Yukon Gear – Polished Aluminum Cover For GM 12 Bolt Truck (Part No.32027)

    Polished Aluminum Cover For GM 12 Bolt Truck

    from

    $269.99
    Polished aluminum cover for 12T GM.

    Product Features:
    • Fits GM 12 bolt truck
    • Finned polished aluminum
    See More

    Top-Quality Rear Housing Cover Gaskets for 1978 GMC G15s

    Choose a high-quality OEM or aftermarket Rear Housing Cover Gasket for GMC G15s and enjoy top-notch performance from $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

    Top Picks for 1978 GMC G15 Differential Bearings

    Invest in one of our 6 durable Differential Bearings for your 1978 GMC, knowing you’re getting trusted brands and expert craftsmanship.

    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 – Multi-Purpose Bearing (Part No.A-36)

    Multi-Purpose Bearing

    from

    $27.99
    Product Features:
    • CONSISTENT PERFORMANCE: Matched cup and cone components ensure consistent performance
    • 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 – 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

    Yukon Gear – Positraction Cross Pin Bolt For GM 12 Bolt Car And Truck (Part No.33344)

    Positraction Cross Pin Bolt For GM 12 Bolt Car And Truck

    from

    $28.99
    Positraction cross pin bolt for GM 12P and 12T.

    Product Features:
    • Cross pin bolt for GM 12 bolt passenger car and truck
    • For OEM positraction applications only
    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
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    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

    Top-Rated Rear Differential Cover Gaskets for 1978 GMC G15s

    Make a smart move for your 1978 GMC G15 with products all priced from $9.49 to $31.49.

    Felpro – Axle Housing Cover Gasket Irregular Shaped 12 Bolt Hole Gasket (Part No.RDS 13391)

    Axle Housing Cover Gasket Irregular Shaped 12 Bolt Hole Gasket

    from

    $9.49
    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
    • Engineered for the sealing repair environment
    • Validated for fit, form and function
    • Unsurpassed quality you can trust
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    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

    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 – GM 12 Bolt Truck Cover Gasket (Part No.23015)

    GM 12 Bolt Truck Cover Gasket

    from

    $12.99
    12T cover gasket.

    Product Features:
    • Cover gasket
    • Fits GM 12 bolt truck
    See More

    Top-Rated Differential Brands For Your 1978 GMC G15

    When it comes to finding the perfect Differential for your 1978 GMC G15, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 13 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 GMC G15, providing peace of mind with parts that meet or exceed OEM standards.

    Popular National 1978 GMC G15 Differentials

    If you’re looking for a top-quality Differential for your 1978 GMC G15, 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 $11.42, you’ll find the perfect Differential for your needs and budget. National Differentials for the 1978 GMC G15 come highly rated, with over 45 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 $7.99
    (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.”
    Multi-Purpose Bearing
    from $16.99
    (39)
    Multi-Purpose Bearing
    “Great bearings”

    Top-Quality DriveWorks 1978 GMC G15 Differentials

    For those in search of a high-quality Differential for their 1978 GMC G15, Advance Auto Parts offers a great selection of DriveWorks Differentials. With 2 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, with an average price of $8.89, giving you a range of options to suit your budget. Backed by over 2 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.”
    Oil Seal
    from $9.79
    (1)
    Oil Seal
    “Great fitment”

    FAQs for 1978 GMC G15 Differentials

    What are the best-selling Differentials for 1978 GMC G15s?

    Out of 196 Differentials that fit 1978 GMC G15s, the following parts are the top sellers:

    What’s the price range for 1978 GMC G15 Differentials?

    The prices of Differentials for the 1978 GMC G15 range from $2.59 up to $1,969.99 for the most premium parts.

    What is the average price of a Differential for a 1978 GMC G15?

    The average price for Differentials for the 1978 GMC G15 is $256.45. 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 GMC G15 model years?

    Yes, we carry Differentials for 2 model years of GMC G15s between 1975 and 1977. The following model years are the most popular for Differential purchases: 1977, 1976, and 1975.

    What are the cheapest Differentials for my 1978 GMC G15?

    The cheapest 1978 GMC G15 Differentials we carry are:

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

    Yes. We stock Differentials for 12 other popular 1978 GMC models. Some of the most popular are 1978 Jimmy Differentials, 1978 Caballero Differentials, 1978 K25 Differentials, 1978 K15 Differentials, and 1978 G25 Differentials.

    What types of Differentials do you sell for my 1978 GMC G15?

    As of 11/2/25, these are some of the most in-demand types of Differentials for a 1978 GMC G15:

    Can I get help with 1978 GMC G15 Differential orders?

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

    What is your return policy for GMC G15 Differentials?

    Advance Auto Parts keeps returns simple. For new GMC G15 Differentials and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.