1978 GMC K25 Differentials

Keep Your 1978 GMC K25 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 K25 looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Differential Bearings, Differential Oil, and Differential Covers. 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 FELPRO. For example, National Differentials start at just $7.99 with an average 4.3 star rating. Motive Gear and FELPRO offer similar pricing and quality, backed by strong customer feedback. With over 1,896 reviews and a solid 4 star average, you can shop with confidence knowing other GMC K25 owners approve.

Competitive Prices and Extensive Inventory

The average price for a 1978 GMC K25 Differential at Advance Auto Parts is around $227.22, with a range that starts at $0.91 and goes up to $1,497.99. With 392 options in stock from 14 trusted brands, finding the right fit is easy. Popular picks like DEXRON – VI ATF Full Synthetic Automatic Transmission Fluid, 1 Quart, DEX/MERC ATF Conventional Automatic Transmission Fluid, 1 Quart, and Differential Shaft Lock Bolt start at just $6.79 and offer a great balance of form and function.

Explore Related Parts

While you’re upgrading or replacing your Differential, don’t forget to check out other key components like 4WD Components and Universal Joints. At Advance Auto Parts, we’re here to help you keep your 1978 GMC K25 in peak condition, inside and out.

Essential 1978 GMC K25 Differentials

National – Tapered Roller Bearing Cone (Part No.HM803149)

Tapered Roller Bearing Cone

from

$36.99
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 – Standard Open Cross Pin (0.795" Diameter) For 8.5" GM – Fits Some Eaton Positractions (Part No.33401)

Standard Open Cross Pin (0.795" Diameter) For 8.5" GM - Fits Some Eaton Positractions

from

$49.99
Standard open cross pin (0.795″ diameter) for 8.5″ GM. fits some Eaton positractions.

Product Features:
  • Cross pin shaft for GM 8.5″ and 8.6″
  • Fits standard open differentials only
  • 0.795″ diameter
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Motive Gear – Differential Gear Install Kit (Part No.GM10.5IK)

Differential Gear Install Kit

from

$54.99


Product Features:
  • MINI INST KIT GM 14BLT 10.5″ 4.10DN 1972-88
See More

Yukon Gear – Standard Open Spider Gear Kit For 8.5" GM With 30 Spline Axles (Part No.16055)

Standard Open Spider Gear Kit For 8.5" GM With 30 Spline Axles

from

$207.99
Yukon standard open spider gear kit for 8.5″ GM with 30 spline axles. Yukon uses higher quality materials and better techniques than OEM to ensure a longer lasting spider gear set. All components come with a one year warranty against manufacturing defects.

Product Features:
  • Spider gear kit
  • Fits GM 8.5″ open differential with 30 spline axles
  • Includes two side gears, two pinion gears, cross pin shaft, cross pin bolt and spider gear thrust washers.
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Yukon Gear – DiffrlPinSupportBolt (Part No.33582)

DiffrlPinSupportBolt

from

$5.99
DiffrlPinSupportBolt

National – Tapered Roller Bearing Cone (Part No.LM104949)

Tapered Roller Bearing Cone

from

$21.99
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 – 14T Side Gear Thrust Washer (Part No.33383)

14T Side Gear Thrust Washer

from

$7.99
14T side gear Thrust washer.

Product Features:
  • Side gear thrust washer
  • Fits GM 10.5″ 14 bolt truck
See More

Motive Gear – Differential Master Bearing Kit – Timken (Part No.R10REMKT)

Differential Master Bearing Kit - Timken

from

$137.99
Motive Gear Differential Bearing Kits Include Front & Rear Pinion Bearing, Pinion Seal, Carrier Bearings, Pilot Bearing Where Applicable, Gear Marking Compound, Crush Sleeve, Pinion Nut, Brush, Thread Locking Compound And Cover Gasket Or Rtv

Product Features:
  • GM 10 BOLT 8.5 BRG MSTR KIT W/EATON OR AUBURN PRO TIMKEN
See More

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

Dura Grip Positraction For GM 8.5" With 28 Spline Axles

from

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

Product Features:
  • Fits GM 8.5″ with 28 spline axles
  • 2.73 ratio and up only
  • 4-spring, clutch style positraction
  • Internal gears are manufactured using forged 4320 steel and cut to provide stronger teeth
  • Fully rebuildable
  • Assembled in the USA
See More

Yukon Gear – Dana 25 / 27 / 30 / 36 / 44 / 53 Pinion Nut Washer Replacement (Part No.33163)

Dana 25 / 27 / 30 / 36 / 44 / 53 Pinion Nut Washer Replacement

from

$3.99
Replacement pinion nut washer for Dana 25, 27, 30, 36, 44 & 53.

Product Features:
  • Pinion nut washer for Dana Spicer 25, 27, 30, 44 and 50
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USA Standard Gear – Ring & Pinion Gear Set For 10.5" GM 14 Bolt Truck In A 4.56 Ratio (Part No.36184)

Ring & Pinion Gear Set For 10.5" GM 14 Bolt Truck In A 4.56 Ratio

from

$339.99
USA Standard ring & pinion sets are the right choice to add confidence to your install. USA Standard Gear offers a full line of ring & pinion sets for a variety of common & hard to find applications. USA standard gear offers a standard one year warranty against defects on their ring & pinion sets.

Product Features:
  • Fits GM 10.5″ GM 14 bolt truck
  • 10.50″ ring gear diameter
  • 30 spline pinion
  • 12 ring gear bolts
  • 4.56 ratio
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Driveworks – Wheel Bearing (Part No.S-R1581-TV)

Wheel Bearing

from

$27.99
Product Features:
  • Brand may vary by location
See More

Yukon Gear – Set Up Bearing (Part No.56037)

Set Up Bearing

from

$189.99
Set-up carrier bearing (2 bearings, no races) 25590. No return.

Product Features:
  • Set up bearing kit
  • Fits Dana Spicer 44
  • Easily slips on and off carrier journals to allow for easier carrier shim adjustment
See More

Yukon Gear – Replacement Yoke For Dana 30, 44, And 50 With 26 Spline And A 1330 U/Joint Size (Part No.41020)

Replacement Yoke For Dana 30, 44, And 50 With 26 Spline And A 1330 U/Joint Size

from

$125.99
Yukon replacement yoke for Dana 30, 44, and 50 with 26 spline and a 1330 U/joint size. 3.625″ snap ring span, 1.125″ cap diameter. Outside snap ring. This yoke uses u-bolts. All Yukon yokes come with a one year warranty against manufacturing defects.

Product Features:
  • Fits Dana Spicer 44
  • 26 spline
  • 1330 u-joint size
  • 3.625″ snap ring span
  • 1.125″ cap diameter
  • Outside snap ring design
  • U-bolt style
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Yukon Gear – Seal Housing For Dana 44, Zip Locker, With O-Rings (Part No.34013)

Seal Housing For Dana 44, Zip Locker, With O-Rings

from

$83.99
Product Features:
  • Seal housing for Dana Spicer 44
  • Includes o-rings
See More

Motive Gear – Axle Shaft (Part No.MG1775)

Axle Shaft

from

$141.99
The Motive Gear replacement axle shaft offers an OE-quality axle shaft at a fraction of the OE cost. Manufactured from 1541H material on high-tolerance CNC equipment, this axle shaft is designed to provide a perfect fit every time.

Product Features:
  • AXLE SHAFT GM 10.5″ 30 SPL. 31 11/16″ L.H.
See More

Yukon Gear – Powr Lok Button Kit For Dana 30, Dana 44 & Chrysler 8.75" (Part No.33536)

Powr Lok Button Kit For Dana 30, Dana 44 & Chrysler 8.75"

from

$67.99
Yukon Ring & Pinion sets give you the confidence of knowing you’re running gears designed for the harshest of conditions. Whether it’s on the street, off-road, or at the track; Yukon ring & pinion sets deliver unrivaled performance & quality. Yukon uses t

Product Features:
  • Powr Lok button kit
  • Fits Dana Spicer 30, 44 and Chrysler 8.75″
See More

Yukon Gear – Replacement Ring Gear Bolt For Model 35, Dana 25, 27, 30 & 44 – 3/8" X 24 (Part No.33038)

Replacement Ring Gear Bolt For Model 35, Dana 25, 27, 30 & 44 - 3/8" X 24

from

$11.99
Replacement ring gear bolt for Model 35, Dana 25, 27, 30 & 44. 3/8″ x 24.

Product Features:
  • Ring gear bolt for Dana Spicer 25, 27, 30, 44 and AMC Model 35
  • 3/8″ x 24 thread
See More

Yukon Gear – Replacement Oil Baffle For Dana 44 (Part No.33000)

Replacement Oil Baffle For Dana 44

from

$6.99
Product Features:
  • Oil baffle for Dana Spicer 44
See More

Yukon Gear – The Carrier Bearing Puller (Part No.56072)

The Carrier Bearing Puller

from

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

Product Features:
  • Carrier bearing puller
  • Works with an impact gun to safely and easliy remove carrrier bearings
See More

Yukon Gear – Steel Cover For GM 10.5" 14 Bolt Truck (Part No.32345)

Steel Cover For GM 10.5" 14 Bolt Truck

from

$92.99
Product Features:
  • Fits GM 10.5″ 14 bolt truck
  • Steel
See More

Yukon Gear – 8.5 Front Cover Gasket (Part No.23021)

8.5 Front Cover Gasket

from

$11.99
8.5 front cover gasket.

Product Features:
  • Cover gasket
  • Fits GM 8.5″ front
See More

Yukon Gear – Bearing Race Driver (Part No.56009)

Bearing Race Driver

from

$188.99
Bearing race driver. No return.

Product Features:
  • Bearing race driver
  • Fits 382A race
  • All steel construction
See More

Yukon Gear – Super Carrier Shim Kit For Ford 7.5", GM 7.5", 8.2" & 8.5" (Part No.55001)

Super Carrier Shim Kit For Ford 7.5", GM 7.5", 8.2" & 8.5"

from

$59.99
Product Features:
  • Super carrier shim kit for Ford 7.5″, GM 7.5″, 7.625″, 7.6″ IFS, 7.6″ IRS, 7.75″, 8.2″, 8.2″ Buick, Oldsmobile and Pontiac and GM 8.5″ front and rear
  • Interlocking design makes installation much easier
See More

Yukon Gear – Dura Grip Positraction For GM 8.5" & 8.6" With 30 Spline Axles (Part No.26016)

Dura Grip Positraction For GM 8.5" & 8.6" With 30 Spline Axles

from

$929.99
The Yukon Dura Grip provides aggressive yet smooth traction to give you the confidence & performance you need. Get longer life and better traction with the heavy duty Yukon Dura Grip Positraction. The Yukon Dura Grip uses a nodular case and forged 4320 internals for added strength along with composite clutches for high performance and long life. All units are Rebuildable and many offer upgrades to increase aggressiveness for racing applications. Each unit carries a one year warranty against defects. This unit has larger bearing journals for added strength & uses heavy-duty carrier bearings & races.

Product Features:
  • Fits GM 8.5″ and 8.6″ with 30 spline axles
  • 2.73 ratio and up only
  • 4-spring, clutch style positraction
  • Internal gears are manufactured using forged 4320 steel and cut to provide stronger teeth
  • Fully rebuildable
  • Assembled in the USA
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 – 10.5" GM 14 Bolt Truck Pinion Nut (Part No.33148)

10.5" GM 14 Bolt Truck Pinion Nut

from

$48.99
10.5″ GM 14 bolt truck pinion nut. 1 1/2″ socket, 15/16″ x 16 thread.

Product Features:
  • Pinion nut for GM 10.5″ 14 bolt truck
  • 15/16″ x 16 thread
  • 1.5″ socket
See More

USA Standard Gear – Master Overhaul Kit for the ’88 and Older GM 10.5" 14T Differential (Part No.37044)

Master Overhaul Kit for the '88 and Older GM 10.5" 14T Differential

from

$349.99
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 1988 and down GM 10.5″ 14 bolt truck
  • Uses Koyo bearings and races
  • Included are carrier bearings and races, pinion bearings and races, pilot bearing, pinion seal, complete shim kit, pinion nut, crush sleeve, thread locker, marking compound with brush and gasket.
See More

Popular 1978 GMC K25 Differentials Categories

Most Popular Differential Bearings for 1978 GMC K25s

Enhance your 1978 GMC K25 with one of the 11 Differential Bearings we have in stock, starting at just $6.99.

National – Bearing Race (Part No.382A)

Bearing Race

from

$10.99
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.LM501314)

Bearing Race

from

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

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

National – Tapered Roller Bearing Cone (Part No.LM104949)

Tapered Roller Bearing Cone

from

$21.99
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

Driveworks – Tapered Cone Wheel Bearing Assembly (Part No.S-387-AS)

Tapered Cone Wheel Bearing Assembly

from

$18.49
Value-priced bearing meets all cataloged application requirements.

Product Features:
  • Brand may vary by location
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.LM501310)

Bearing Race

from

$8.49
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

National – Bearing Race (Part No.25523)

Bearing Race

from

$19.99
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

FAG US – Cup (Part No.M88010)

Cup

from

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

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

FAG US – Cup (Part No.LM501310)

Cup

from

$9.99
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

Best-Selling 1978 GMC K25 Differential Oil

Upgrade your K25 with one of our 5 best-selling Differential Oil, earning an average 5 stars rating across 2 reviews.

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

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

from

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

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

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

DEX/MERC ATF Conventional Automatic Transmission Fluid, 1 Quart

from

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

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

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

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

from

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

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

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

Redline Synthetic "Shock Proof" Oil - 3 Quarts

from

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

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

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

Redline Synthetic "Shock Proof" Oil - 4 Quarts

from

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

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

Top-Quality Differential Covers for 1978 GMC K25s

Choose a high-quality OEM or aftermarket Differential Cover for GMC K25s and enjoy top-notch performance from $44.99.

Yukon Gear – Replacement Chrome Cover For Dana 44 (Part No.32004)

Replacement Chrome Cover For Dana 44

from

$67.99
0.080″ thick Chrome replacement cover for Dana 44.

Product Features:
  • Fits standard rotation Dana Spicer 44
  • Chrome
See More

Yukon Gear – Chrome Cover For 8.5" GM Front (Part No.32016)

Chrome Cover For 8.5" GM Front

from

$44.99
Chrome cover for 8.5″ GM front.

Product Features:
  • Fits GM 8.5″ front
  • Chrome
See More

Yukon Gear – Steel Cover For GM 10.5" 14 Bolt Truck (Part No.32345)

Steel Cover For GM 10.5" 14 Bolt Truck

from

$92.99
Product Features:
  • Fits GM 10.5″ 14 bolt truck
  • Steel
See More

Yukon Gear – Chrome Cover For 10.5" GM 14 Bolt Truck (Part No.32013)

Chrome Cover For 10.5" GM 14 Bolt Truck

from

$59.99
Chrome cover for GM 14T.

Product Features:
  • Fits GM 10.5″ 14 bolt truck
  • Chrome
See More

Yukon Gear – Steel Cover For Dana 44 Standard Rotation (Part No.32319)

Steel Cover For Dana 44 Standard Rotation

from

$129.99
Product Features:
  • Fits standard rotation Dana Spicer 44
  • Steel
See More

Yukon Gear – Aluminum Girdle Replacement Cover For Dana 44 Ta HD (Part No.32110)

Aluminum Girdle Replacement Cover For Dana 44 Ta HD

from

$359.99
Aluminum Girdle replacement cover for Dana 44 TA HD.

Product Features:
  • Fits standard rotation Dana Spicer 44
  • Aluminum girdle cover
See More

Yukon Gear – Polished Aluminum Cover For 8.5" GM (Part No.32029)

Polished Aluminum Cover For 8.5" GM

from

$296.99
Polished aluminum cover for 8.5″ GM.

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

Yukon Gear – Differential (Part No.29101)

Differential

from

$271.99
Differential

Top Picks for 1978 GMC K25 Rear Differential Cover Gaskets

Invest in one of our 5 durable Rear Differential Cover Gaskets for your 1978 GMC, knowing you’re getting trusted brands and expert craftsmanship.

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

Differential Gasket

from

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

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

Felpro – Axle Housing Cover Gasket: Irregular Shaped 14 Bolt Hole Gasket (Part No.RDS 55063)

Axle Housing Cover Gasket: Irregular Shaped 14 Bolt Hole Gasket

from

$8.29
Fel-Pro® gaskets are specifically designed for the repair environment to deliver a reliable seal on even the most troublesome applications. Designed for imperfect sealing surfaces and manufactured with proprietary materials, you can count on Fel-Pro for innovative sealing solutions for the real-world repair environment.

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered for the sealing repair environment
  • Validated for fit, form and function
  • Unsurpassed quality you can trust
See More

Yukon Gear – GM 10.5′ 14 Bolt Truck Cover Gasket (Part No.23016)

GM 10.5' 14 Bolt Truck Cover Gasket

from

$13.99
14T cover gasket.

Product Features:
  • Cover gasket
  • Fits GM 10.5″ 14 bolt truck
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.
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Yukon Gear – Dana 44 Cover Gasket Replacement (Part No.23006)

Dana 44 Cover Gasket Replacement

from

$12.99
Product Features:
  • Cover gasket
  • Fits Dana Spicer 44
See More

Top-Rated Rear Housing Cover Gaskets for 1978 GMC K25s

Make a smart move for your 1978 GMC K25 with products all priced from $7.99 to $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
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Felpro – Axle Housing Cover Gasket Irregular Shaped 10 Bolt Hole Gasket (Part No.RDS 6629)

Axle Housing Cover Gasket Irregular Shaped 10 Bolt Hole Gasket

from

$7.99
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
See More

Top-Rated Differential Brands For Your 1978 GMC K25

When it comes to finding the perfect Differential for your 1978 GMC K25, 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 FELPRO, National, and Motive Gear, and more, all known for their exceptional customer ratings (average brand rating of 4.6 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 K25, providing peace of mind with parts that meet or exceed OEM standards.

Popular FELPRO 1978 GMC K25 Differentials

If you’re looking for a top-quality Differential for your 1978 GMC K25, Advance Auto Parts has exactly what you need with our selection of FELPRO Differentials. We have 3 FELPRO 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 $9.09, you’ll find the perfect Differential for your needs and budget. FELPRO Differentials for the 1978 GMC K25 come highly rated, with over 218 customer reviews and an impressive average rating of 4.6 stars. Choosing a FELPRO Differential from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.
Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket
from $10.99
(195)
Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket
“Worked as described”

Top-Quality National 1978 GMC K25 Differentials

For those in search of a high-quality Differential for their 1978 GMC K25, Advance Auto Parts offers a great selection of National Differentials. With 3 National 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 $9.42, giving you a range of options to suit your budget. Backed by over 12 customer ratings and an average rating of 4.3 stars, National Differentials provide both reliability and excellent performance. Choosing a National Differential from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
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.”
Bearing Race
from $10.99
(6)
Bearing Race
“Fit perfectly. No difficulty replacing my old ones.”

FAQs for 1978 GMC K25 Differentials

What are the best-selling Differentials for 1978 GMC K25s?

Out of 392 Differentials that fit 1978 GMC K25s, the following parts are the top sellers:

What’s the price range for 1978 GMC K25 Differentials?

The prices of Differentials for the 1978 GMC K25 range from $0.91 up to $1,497.99 for the most premium parts.

What is the average price of a Differential for a 1978 GMC K25?

The average price for Differentials for the 1978 GMC K25 is $227.22. 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 K25 model years?

Yes, we carry Differentials for 2 model years of GMC K25s 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 K25?

The cheapest 1978 GMC K25 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 K15 Differentials, 1978 G25 Differentials, and 1978 C25 Differentials.

What are the top-rated Differentials that fit the 1978 GMC K25?

The one 1978 GMC K25 Differential we have in stock is the Differential Ring Gear Bolt. It costs $0.91.

What types of Differentials do you sell for my 1978 GMC K25?

As of 11/2/25, these are some of the most in-demand types of Differentials for a 1978 GMC K25:

Can I get help with 1978 GMC K25 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 K25 Differentials?

Advance Auto Parts keeps returns simple. For new GMC K25 Differentials and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.