1978 GMC P15 Differentials

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Keep Your 1978 GMC P15 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 P15 looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Rear Housing Cover Gaskets, Differential Bearings, and Rear Differential 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 Driveworks, Richmond Gear, and Felpro. For example, Driveworks Differentials start at just $8.99 with an average 4.2 star rating. Richmond Gear and Felpro offer similar pricing and quality, backed by strong customer feedback. With over 280 reviews and a solid 4.5 star average, you can shop with confidence knowing other GMC P15 owners approve.

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 P15 in peak condition, inside and out.

Essential 1978 GMC P15 Differentials

Motive Gear – Motive Gear Differential Mini Spool, MS12C (Part No.MS12C)

Motive Gear Differential Mini Spool, MS12C

from

$108.99
Motive Gear Differential Mini Spool, MS12C.
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Powertrax – Powertrax Differential Lock Assembly, 9207883005 (Part No.9207883005)

Powertrax Differential Lock Assembly, 9207883005

from

$551.99
For vehicles that are driven daily, the Power Trax 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 Power Trax No-Slip locker easily installs in to your differential carrier using basic tools and without affecting your ring and pinion settings. Power Trax Grip-Lok, Lock-Right Lockers and No-Slip Traction Systems automatically provide 100% traction on-demand, under the toughest circumstances. The Power Trax Grip-Pro and Grip-LS performance limited slips offer smooth dependable torque transfer and traction for the best of both worlds.
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Motive Gear – Motive Gear Differential Gear Install Kit, GM12IK (Part No.GM12IK)

Motive Gear Differential Gear Install Kit, GM12IK

from

$69.99
Motive Gear Differential Gear Install Kit, GM12IK.
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Driveworks – Driveworks Taper Bearing Set, S-A-5 (Part No.S-A-5)

Driveworks Taper Bearing Set, S-A-5

from

$11.99
Value-priced bearing meets all cataloged application requirements.
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Victor Reinz – Victor Reinz Axle Housing Cover Gasket, 71-14826-00 (Part No.71-14826-00)

Victor Reinz Axle Housing Cover Gasket, 71-14826-00

from

$9.99
With Victor Reinz gaskets, you can be sure you are getting sealing solutions that deliver OE quality gasket technology and engineering. That is because Victor Reinz is an original equipment supplier and the trusted choice of manufacturers the world over, offering broad coverage for foreign and domestic cars and trucks. In Victor Reinz gasket sets, you get the right combination of components needed for fast, long-lasting repairs.
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National – National Shaft Repair Sleeve, 99170 (Part No.99170)

National Shaft Repair Sleeve, 99170

from

$47.49
National has built a reputation as one of the most respected names in the industry. We have offered premium sealing solutions for more than 75 years. Our design team keeps pace with the industry and provides advanced solutions for today’s vehicles.
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Motive Gear – Motive Gear Differential Master Bearing Kit – Timken, R12RMKT (Part No.R12RMKT)

Motive Gear Differential Master Bearing Kit - Timken, R12RMKT

from

$119.99
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
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Pro-King – Pro-King Differential Ring Gear Bolt, 742J935 (Part No.742J935)

Pro-King Differential Ring Gear Bolt, 742J935

from

$0.91
Pro-King is the leading supplier of transmission and driveline products in the aftermarket.
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Felpro – Felpro Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket, RDS 55028-1 (Part No.RDS 55028-1)

Felpro Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket, RDS 55028-1

from

$11.99
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.
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Pro-King – Pro-King Differential Pinion Shim Kit, 742G200A (Part No.742G200A)

Pro-King Differential Pinion Shim Kit, 742G200A

from

$18.49
Pro-King is the leading supplier of transmission and driveline products in the aftermarket.
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National – National Bearing Race, HM89410 (Part No.HM89410)

National Bearing Race, HM89410

from

$11.49
Manufactured with premium-grade steel, National taper bearing cups feature crowned raceways to ensure even load distribution.
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Pro-King – Pro-King Differential Cross Shaft, 742G930 (Part No.742G930)

Pro-King Differential Cross Shaft, 742G930

from

$2.99
Pro-King is the leading supplier of transmission and driveline products in the aftermarket.
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Motive Gear – Motive Gear Differential Crush Sleeve, 3954482 (Part No.3954482)

Motive Gear Differential Crush Sleeve, 3954482

from

$5.99
Motive Gear Differential Crush Sleeve, 3954482.
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Driveworks – Driveworks Oil Seal, S-8460N (Part No.S-8460N)

Driveworks Oil Seal, S-8460N

from

$8.99
Value-priced seal meets all cataloged application requirements.
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Motive Gear – Motive Gear Differential Pinion Shim Kit, 1104 (Part No.1104)

Motive Gear Differential Pinion Shim Kit, 1104

from

$12.99
Motive Gear Differential Pinion Shim Kit, 1104.
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Driveworks – Driveworks Tapered Roller Bearing, S-LM-603012 (Part No.S-LM-603012)

Driveworks Tapered Roller Bearing, S-LM-603012

from

$7.99
Driveworks Tapered Roller Bearing, S-LM-603012.
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Driveworks – Driveworks Wheel Bearing Kit, S-RA-321 (Part No.S-RA-321)

Driveworks Wheel Bearing Kit, S-RA-321

from

$141.99
Driveworks Wheel Bearing Kit, S-RA-321.
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Pro-King – Pro-King Differential Cover Plug, 742G484 (Part No.742G484)

Pro-King Differential Cover Plug, 742G484

from

$6.99
Pro-King is the leading supplier of transmission and driveline products in the aftermarket.
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National – National Tapered Roller Bearing Cone, HM89449 (Part No.HM89449)

National Tapered Roller Bearing Cone, HM89449

from

$25.49
Manufactured with premium-grade steel, National taper bearing cones feature crowned raceways and rollers to ensure even load distribution.
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Driveworks – Driveworks Tapered Roller Bearing, S-M-802048 (Part No.S-M-802048)

Driveworks Tapered Roller Bearing, S-M-802048

from

$17.99
Driveworks Tapered Roller Bearing, S-M-802048.
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Yukon Gear – Yukon Gear 3 Qt – Penzoil 80W90 Conventional Gear Oil, 15002 (Part No.15002)

Yukon Gear 3 Qt - Penzoil 80W90 Conventional Gear Oil, 15002

from

$44.99
Union 76 gear oil is a conventional non-synthetic 80W90 formulation designed for all types of differentials.
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Valvoline – Valvoline Multi-Vehicle (ATF) Full Synthetic Automatic Transmission Fluid 1 GA, 904891 (Part No.904891)

Valvoline Multi-Vehicle (ATF) Full Synthetic Automatic Transmission Fluid 1 GA, 904891

from

$35.99
Choosing an automatic transmission fluid just got easier. Valvoline Full Synthetic MaxLife Multi-Vehicle ATF, the #1 ATF product, is suitable for use in 95% of ATF vehicles in operation with US registered light duty applications. And now, it€™s also recommended for most belt and chain-driven continuously variable transmissions (CVT). Featuring advanced additives to prevent the major causes of transmission breakdown, it€™s designed to help prevent leaks, reduce wear and tear, and maximize performance €“ all for much longer than conventional fluids. It has improved thermal stability for longer fluid life, better viscosity stability for consistent transmission operation, and frictional enhancements for smooth gear engagements. Whether your vehicle has a CVT or traditional automatic, Valvoline MaxLife Multi-Vehicle ATF is suitable for a broad range of transmissions including Ford, GM, Toyota, Honda, Nissan, Hyundai, Subaru, BMW, Mercedes, Volvo, VW and Audi vehicles. It€™s specifically recommended for use in the following applications: GM DEXRON-II, DEXRON-III, DEXRON-VI, and DEX-CVT; Ford MERCON LV; Toyota/Lexus Type T, T-II, T-IV, WS, CVTF FE, and CVTF TC. For the many miles ahead, trust your transmission with Valvoline, the #1 automatic transmission fluid brand.
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Richmond Gear – Richmond Gear Differential Pinion Shaft, 80-0269-1 (Part No.80-0269-1)

Richmond Gear Differential Pinion Shaft, 80-0269-1

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.
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Dorman – Dorman Axle Shaft, 630-128 (Part No.630-128)

Dorman Axle Shaft, 630-128

from

$143.99
This axle shaft is designed to match the performance of the original equipment shaft on specified vehicle makes, models and years. When a factory axle shaft fails or is damaged by rust or collision, this replacement is engineered to help restore and ensure the proper transfer of torque and rotational power from the differential or transmission to the wheel.
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Dorman – Dorman Rear Axle Shaft, Left Or Right, 630-128A (Part No.630-128A)

Dorman Rear Axle Shaft, Left Or Right, 630-128A

from

$123.99
This axle shaft is designed to match the performance of the original equipment shaft on specified vehicle makes, models and years. When a factory axle shaft fails or is damaged by rust or collision, this replacement is engineered to help restore and ensure the proper transfer of torque and rotational power from the differential or transmission to the wheel.
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Motive Gear – Motive Gear Differential Ring and Pinion, GM12-373 (Part No.GM12-373)

Motive Gear Differential Ring and Pinion, GM12-373

from

$313.99
Motive Gear Differential Ring and Pinion, GM12-373.
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Motive Gear – Motive Gear Differential Ring and Pinion, GM12-411 (Part No.GM12-411)

Motive Gear Differential Ring and Pinion, GM12-411

from

$205.99
Motive Gear Differential Ring and Pinion, GM12-411.
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Motive Gear – Motive Gear Differential Ring and Pinion, GM12-411A (Part No.GM12-411A)

Motive Gear Differential Ring and Pinion, GM12-411A

from

$183.99
Motive Gear Differential Ring and Pinion, GM12-411A.
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Most Popular Rear Housing Cover Gasket for 1978 GMC P15s

Enhance your 1978 GMC P15 with this popular Rear Housing Cover Gasket we have in stock, for $9.99.

Victor Reinz – Victor Reinz Axle Housing Cover Gasket, 71-14826-00 (Part No.71-14826-00)

Victor Reinz Axle Housing Cover Gasket, 71-14826-00

from

$9.99
With Victor Reinz gaskets, you can be sure you are getting sealing solutions that deliver OE quality gasket technology and engineering. That is because Victor Reinz is an original equipment supplier and the trusted choice of manufacturers the world over, offering broad coverage for foreign and domestic cars and trucks. In Victor Reinz gasket sets, you get the right combination of components needed for fast, long-lasting repairs.
See More

Best-Selling 1978 GMC P15 Differential Bearings

Upgrade your P15 with one of our 2 best-selling Differential Bearings.

Driveworks – Driveworks Tapered Roller Bearing, S-LM-603012 (Part No.S-LM-603012)

Driveworks Tapered Roller Bearing, S-LM-603012

from

$7.99
Driveworks Tapered Roller Bearing, S-LM-603012.
See More

Driveworks – Driveworks Wheel Bearing Kit, S-RA-321 (Part No.S-RA-321)

Driveworks Wheel Bearing Kit, S-RA-321

from

$141.99
Driveworks Wheel Bearing Kit, S-RA-321.
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Top-Quality Rear Differential Cover Gaskets for 1978 GMC P15s

Choose a high-quality OEM or aftermarket Rear Differential Cover Gasket for GMC P15s and enjoy top-notch performance from $9.49.

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

Felpro Axle Housing Cover Gasket Irregular Shaped 12 Bolt Hole Gasket, RDS 13391

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.
See More

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

Felpro Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket, RDS 55028-1

from

$11.99
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.
See More

Top Picks for 1978 GMC P15 Differential Oil

Invest in one of our 3 durable Differential Oil for your 1978 GMC, knowing you’re getting trusted brands and expert craftsmanship.

Yukon Gear – Yukon Gear 3 Qt – Penzoil 80W90 Conventional Gear Oil, 15002 (Part No.15002)

Yukon Gear 3 Qt - Penzoil 80W90 Conventional Gear Oil, 15002

from

$44.99
Union 76 gear oil is a conventional non-synthetic 80W90 formulation designed for all types of differentials.
See More

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

"Yukon Gear Redline Synthetic ""Shock Proof"" Oil - 4 Quarts, 15004"

from

$137.99
Redline Heavy Shockproof Gear Oil is formulated to provide lasting protection.
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Valvoline – Valvoline Multi-Vehicle (ATF) Full Synthetic Automatic Transmission Fluid 1 GA, 904891 (Part No.904891)

Valvoline Multi-Vehicle (ATF) Full Synthetic Automatic Transmission Fluid 1 GA, 904891

from

$35.99
Choosing an automatic transmission fluid just got easier. Valvoline Full Synthetic MaxLife Multi-Vehicle ATF, the #1 ATF product, is suitable for use in 95% of ATF vehicles in operation with US registered light duty applications. And now, it€™s also recommended for most belt and chain-driven continuously variable transmissions (CVT). Featuring advanced additives to prevent the major causes of transmission breakdown, it€™s designed to help prevent leaks, reduce wear and tear, and maximize performance €“ all for much longer than conventional fluids. It has improved thermal stability for longer fluid life, better viscosity stability for consistent transmission operation, and frictional enhancements for smooth gear engagements. Whether your vehicle has a CVT or traditional automatic, Valvoline MaxLife Multi-Vehicle ATF is suitable for a broad range of transmissions including Ford, GM, Toyota, Honda, Nissan, Hyundai, Subaru, BMW, Mercedes, Volvo, VW and Audi vehicles. It€™s specifically recommended for use in the following applications: GM DEXRON-II, DEXRON-III, DEXRON-VI, and DEX-CVT; Ford MERCON LV; Toyota/Lexus Type T, T-II, T-IV, WS, CVTF FE, and CVTF TC. For the many miles ahead, trust your transmission with Valvoline, the #1 automatic transmission fluid brand.
See More

Our Top-Rated Differential Carrier Bearing Set for 1978 GMC P15s

Make a smart move for your 1978 GMC P15 with our Differential Carrier Bearing Set for $11.99.

Driveworks – Driveworks Taper Bearing Set, S-A-5 (Part No.S-A-5)

Driveworks Taper Bearing Set, S-A-5

from

$11.99
Value-priced bearing meets all cataloged application requirements.
See More

Top-Rated Differential Brands For Your 1978 GMC P15

When it comes to finding the perfect Differential for your 1978 GMC P15, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 12 trusted brands. We carry the most popular Differential brands including Felpro, Richmond Gear, and Driveworks, and more, all known for their exceptional customer ratings (average brand rating of 4.6 stars) and competitive prices, as low as $8.99. Purchasing a Differential from us here at Advance Auto Parts is a smart move for both you and your 1978 GMC P15, providing peace of mind with parts that meet or exceed OEM standards.

Popular Felpro 1978 GMC P15 Differentials

If you’re looking for a top-quality Differential for your 1978 GMC P15, Advance Auto Parts has exactly what you need with our selection of Felpro Differentials. We have 2 Felpro Differentials in stock for this fitment, all known for their durability and precision fit. With prices starting at just $9.49 and an average cost of $10.74, you’ll find the perfect Differential for your needs and budget. Felpro Differentials for the 1978 GMC P15 come highly rated, with over 198 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.
Felpro Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket, RDS 55028-1
from $11.99
(195)
Felpro Axle Housing Cover Gasket Oval Shaped 10 Bolt Hole Gasket, RDS 55028-1
“Product easy to put on and easy to work with worked great so far”

Top-Quality Richmond Gear 1978 GMC P15 Differentials

For those in search of a high-quality Differential for their 1978 GMC P15, Advance Auto Parts offers a great selection of Richmond Gear Differentials. With 2 Richmond Gear 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 $350.99, with an average price of $355.99, giving you a range of options to suit your budget. Backed by over 3 customer ratings and an average rating of 4.4 stars, Richmond Gear Differentials provide both reliability and excellent performance. Choosing a Richmond Gear Differential from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
Richmond Gear Differential Ring And Pinion, 69-0298-1
from $360.99
(1)
Richmond Gear Differential Ring And Pinion, 69-0298-1
“Best ever!!!’nn”
Richmond Gear Differential Ring And Pinion, 49-0072-1
from $350.99
(2)
Richmond Gear Differential Ring And Pinion, 49-0072-1
“I have a Chevy Impala 07 that runs on 3 cylinders when not needing the power of 6, and the new plugs have significantly provided an inexpensive tuneup”

FAQs for 1978 GMC P15 Differentials

What are the best-selling Differentials for 1978 GMC P15s?

Out of 56 Differentials that fit 1978 GMC P15s, the following parts are the top sellers:

What’s the price range for 1978 GMC P15 Differentials?

The prices of Differentials for the 1978 GMC P15 range from $0.91 up to $551.99 for the most premium parts.

What is the average price of a Differential for a 1978 GMC P15?

The average price for Differentials for the 1978 GMC P15 is $112.13. 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 P15 model years?

Yes, we carry Differentials for 2 model years of GMC P15s 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 P15?

The cheapest 1978 GMC P15 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 P15?

As of 8/2/26, these are some of the most in-demand types of Differentials for a 1978 GMC P15:

Can I get help with 1978 GMC P15 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 P15 Differentials?

Advance Auto Parts keeps returns simple. For new GMC P15 Differentials and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.