1978 GMC C15 Differentials

Keep Your 1978 GMC C15 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 C15 looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Rear Differential Cover Gaskets, Differential Bearings, 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, 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 3,373 reviews and a solid 4 star average, you can shop with confidence knowing other GMC C15 owners approve.

Competitive Prices and Extensive Inventory

The average price for a 1978 GMC C15 Differential at Advance Auto Parts is around $247.82, with a range that starts at $0.91 and goes up to $1,969.99. With 201 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 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 C15 in peak condition, inside and out.

Essential 1978 GMC C15 Differentials

Motive Gear – Differential Ring and Pinion (Part No.GM12-456A)

Differential Ring and Pinion

from

$187.99


Product Features:
  • GM 12BL 8.875 R/P 4.56A MG
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
See More

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!
  • See More

    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

    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
    See More

    Yukon Gear – Ring Gear Bolt (Part No.33046)

    Ring Gear Bolt

    from

    $6.99
    Ring gear bolt for GM 12 bolt car & truck, 8.2″, 8.2″ for Buick/Olds/Pontiac, 63-79 Corvette & 55-62 GM Car & Truck. 3/8″ x 24.

    Product Features:
    • Ring gear bolt for GM 12 bolt passenger car and truck, 1955-1964 passenger car and truck, GM 8.2″, 8.2″ Buick, Oldsmobile and Pontiac and 1963-1979 Corvette
    • 3/8″ x 24 thread
    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

    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 – 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
    See More

    Yukon Gear – Star Washer For GM 12 Bolt Posi Cross Pin Bolt (Part No.33348)

    Star Washer For GM 12 Bolt Posi Cross Pin Bolt

    from

    $5.99
    Star washer for GM 12 bolt posi cross pin bolt.

    Product Features:
    • Star washer
    • Fits GM 12 bolt passenger car
    See More

    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.
    See More

    Motive Gear – Differential Gear Install Kit (Part No.GM12IK)

    Differential Gear Install Kit

    from

    $69.99


    Product Features:
    • MINI INSTALL KIT GM 12BLT 8.875 TRUCK
    See More

    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

    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
    See More

    Richmond Gear – RngPnnInstlKt (Part No.83-1018-M)

    RngPnnInstlKt

    from

    $224.99
    RngPnnInstlKt

    Yukon Gear – Bearing Race Driver (Part No.56017)

    Bearing Race Driver

    from

    $215.99
    Bearing race driver. No return.

    Product Features:
    • Bearing race driver
    • Fits HM89410 race
    • All steel construction
    See More

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

    MiniSpool

    from

    $151.99
    MiniSpool

    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
    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
    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.
    See More

    FAG US – Repair Sleeve (Part No.SR3506)

    Repair Sleeve

    from

    $53.99
    The FAG repair sleeve is a precision element that provides additional sealing for damaged shafts. Made of heat-treated stainless steel, the FAG repair sleeve signifcantly increases the life of the shaft and prevents premature wear. Since no shaft removal or machining is required during the repair, the repair sleeve is a cost effective repair solution to protect damaged surfaces.

    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

    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 – Minor Install Kit For GM 12 Bolt Truck Differential (Part No.12044)

    Minor Install Kit For GM 12 Bolt Truck Differential

    from

    $151.99
    Yukon Minimum installation kits are a low cost solution for gear changes in newer vehicles where the bearings can be reused. This kit uses all high quality components to ensure a smooth set up. kit includes a pinion seal, crush sleeve (if applicable), complete shim kit, marking compound and brush. (Includes Supershims).

    Product Features:
    • Fits GM 12 bolt truck
    • Included are a pinion seal, crush sleeve, complete shim kit, marking compound and brush.
    See More

    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.
    See More

    Yukon Gear – Set Up Bearing (Part No.56044)

    Set Up Bearing

    from

    $153.99
    HM89449 set-up bearing (one bearing). No return.

    Product Features:
    • Set up bearing
    • Fits HM89449 pinion bearing
    • Easily slips on and off pinion journal to allow for pinion depth adjustment
    See More

    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
    See More

    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

    Most Popular Rear Differential Cover Gaskets for 1978 GMC C15s

    Enhance your 1978 GMC C15 with one of the 4 Rear Differential Cover Gaskets we have in stock, starting at just $9.49.

    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
    See More

    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

    Best-Selling 1978 GMC C15 Differential Bearings

    Upgrade your C15 with one of our 6 best-selling Differential Bearings, earning an average 4 stars rating across 5 reviews.

    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 – 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

    Top-Quality Differential Oil for 1978 GMC C15s

    Choose a high-quality OEM or aftermarket Differential Oil for GMC C15s 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
    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

    Our Top Pick for a 1978 GMC C15 Rear Housing Cover Gasket

    Invest in a durable Rear Housing Cover Gasket for your 1978 GMC, knowing you’re getting trusted brands and expert craftsmanship.

    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

    Differential Covers for 1978 GMC C15s

    Make a smart move for your 1978 GMC C15 with products all priced from $64.99 to $269.99.

    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
    See More

    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-Rated Differential Brands For Your 1978 GMC C15

    When it comes to finding the perfect Differential for your 1978 GMC C15, 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 GMC C15, providing peace of mind with parts that meet or exceed OEM standards.

    Popular National 1978 GMC C15 Differentials

    If you’re looking for a top-quality Differential for your 1978 GMC C15, 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 GMC C15 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 $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.”
    Bearing Race
    from $9.29
    (2)
    Bearing Race
    “Reasonable price and woks well. front diff 2006 Escalade esv”

    Top-Quality DriveWorks 1978 GMC C15 Differentials

    For those in search of a high-quality Differential for their 1978 GMC C15, 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 C15 Differentials

    What are the best-selling Differentials for 1978 GMC C15s?

    Out of 201 Differentials that fit 1978 GMC C15s, the following parts are the top sellers:

    What’s the price range for 1978 GMC C15 Differentials?

    The prices of Differentials for the 1978 GMC C15 range from $0.91 up to $1,969.99 for the most premium parts.

    What is the average price of a Differential for a 1978 GMC C15?

    The average price for Differentials for the 1978 GMC C15 is $247.82. 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 C15 model years?

    Yes, we carry Differentials for 2 model years of GMC C15s 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 C15?

    The cheapest 1978 GMC C15 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 C15?

    As of 11/2/25, these are some of the most in-demand types of Differentials for a 1978 GMC C15:

    Can I get help with 1978 GMC C15 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 C15 Differentials?

    Advance Auto Parts keeps returns simple. For new GMC C15 Differentials and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.