1978 Mercury Cougar Differentials

Essential 1978 Mercury Cougar Differentials

Motive Gear – Differential Mini Spool (Part No.MS88-31)

Differential Mini Spool

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$101.99


Product Features:
  • MINI SPOOL 8.8 FORD 31SPL
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Yukon Gear – DiffrlPinSupport (Part No.32358)

DiffrlPinSupport

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$819.99
DiffrlPinSupport

Yukon Gear – Trac Loc Spring For Ford 9" & 8" (Part No.33518)

Trac Loc Spring For Ford 9" & 8"

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$8.99
Product Features:
  • Trac Loc spring for Ford 8″ and 9″
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Dorman – Ring And Pinion Bearing Installation Kit (Part No.697-101)

Ring And Pinion Bearing Installation Kit

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$164.99
This differential bearing kit includes all necessary installation components for a differential ring and pinion on certain vehicle years, makes and models.

Product Features:
  • Convenient kit – this ring and pinion bearing installation kit includes all necessary components for a complete repair on certain vehicle applications.
  • Related repair – smart to have on hand when installing a differential ring and pinion.
  • Durable construction – built for reliable longevity, free of defects in materials and workmanship
  • Trustworthy quality – backed by team of designers and engineers in the United States
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USA Standard Gear – Master Overhaul Kit for the Ford 9" LM603011 Differential with Daytona Pinion Support (Part No.37038)

Master Overhaul Kit for the Ford 9" LM603011 Differential with Daytona Pinion Support

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$273.99
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 Ford 9″ with LM603011 carrier races and Daytona pinion support
  • 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, pilot bearing, thread locker, marking compound with brush and gasket.
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Yukon Gear – Dana 44, Ford 8" / 9", And Model 20 Side Gear Thrust Washer Replacement (Part No.33283)

Dana 44, Ford 8" / 9", And Model 20 Side Gear Thrust Washer Replacement

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$5.99
Product Features:
  • Side gear thrust washer for Ford 8″, Ford 9″ and AMC Model 20
  • 0.030″ thick
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Yukon Gear – Bearing Race Driver (Part No.56022)

Bearing Race Driver

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$188.99
Bearing race driver. No return.

Product Features:
  • Bearing race driver
  • Fits M86610 race
  • All steel construction
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Yukon Gear – The Carrier Bearing Puller (Part No.56034)

The Carrier Bearing Puller

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$689.99
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 most standard one ton applications. This unit is works with differentials up to one-ton applcations. It is not compatible with 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
  • Not compatible with Dana 70HD, Dana 80, Ford 10.25″ and 10.5″ or Gm and Chrysler 11.5″ applications
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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

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$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 – Trac Loc Clutch Guide For 9" Ford (Part No.33250)

Trac Loc Clutch Guide For 9" Ford

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$4.99
Trac Loc clutch guide for 9″ Ford.

Product Features:
  • Clutch guide
  • Fits Ford 8″ and 9″
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Yukon Gear – Redline Synthetic "Shock Proof" Oil – 3 Quarts (Part No.15000)

Redline Synthetic "Shock Proof" Oil - 3 Quarts

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

Product Features:
  • Includes three quarts of Redline Shockproof oil
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Motive Gear – Differential Gear Install Kit (Part No.F8IK)

Differential Gear Install Kit

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$44.49
All Motive Gear products are engineered for their specific application and manufactured in state of the art facilities. All of our products undergo rigid quality control processes to insure proper fit, performance and longevity. Motive Gear products can be found in the winners circle at NHRA, IHRA, NMRA, NMCA, SODA, SCORE, BITD, Ultra-4 and NASCAR events because we offer unmatched selection and quality demanded by racers and their crew chiefs – the same quality and selection demanded by DIY customers and top mechanics. With four warehouses strategically located across North America, most Motive Gear orders arrive within 2-4 days. Win with Motive Gear!
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Yukon Gear – 8" Ford Pilot Bearing Retainer (Part No.33254)

8" Ford Pilot Bearing Retainer

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$13.99
8″ Ford pilot bearing retainer.

Product Features:
  • Pilot bearing retainer for Ford 8″
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Yukon Gear – Short Cross Pin Shaft Without Block For 9" Ford (Part No.33335)

Short Cross Pin Shaft Without Block For 9" Ford

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$11.99
Short cross pin shaft without block for 9″ Ford.

Product Features:
  • Cross pin shaft
  • Fits Ford 9″
  • Short design
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Yukon Gear – Grizzly Locker, Ford 8.8" With 31 Splines (Part No.28031)

Grizzly Locker, Ford 8.8" With 31 Splines

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$1099.99
The Yukon Grizzly Locker is the ultimate in locking differentials for street, off-road, & drag racing. Grizzly Lockers provide 100% power to both tires, while still allowing for disengagement while negotiating turns. The Yukon Grizzly locker is a mechanical locking differential. It features a forged case and 8620 internals for maximum strength. It’s patented design reduces common locker failures. All units assembled in the USA! All Grizzly Lockers are backed by the best warranty in the business! Yukon covers the replacement unit and covers any collaterally damaged parts and associated labor, up to $2,000!

Product Features:
  • Fits Ford 8.8″ with 31 spline axles
  • Patented internal design reduces common locker failures
  • 8620 internals for added strength
  • Assembled in the USA
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Yukon Gear – Grizzly Locker For Ford 8" With 31 Spline Axles (Part No.28007)

Grizzly Locker For Ford 8" With 31 Spline Axles

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$941.99
The Yukon Grizzly Locker is the ultimate in locking differentials for street, off-road, & drag racing. Grizzly Lockers provide 100% power to both tires, while still allowing for disengagement while negotiating turns. The Yukon Grizzly locker is a mechanical locking differential. It features a forged case and 8620 internals for maximum strength. It’s patented design reduces common locker failures. All units assembled in the USA! All Grizzly Lockers are backed by the best warranty in the business! Yukon covers the replacement unit and covers any collaterally damaged parts and associated labor, up to $2,000!

Product Features:
  • Fits Ford 8″ with 31 spline axles
  • Patented internal design reduces common locker failures
  • 8620 internals for added strength
  • Assembled in the USA
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Yukon Gear – Flat Side Gear Without Hub For 9" Ford With 31 Splines (Part No.16162)

Flat Side Gear Without Hub For 9" Ford With 31 Splines

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$46.99
Flat side gear without hub for 9″ Ford with 31 splines.

Product Features:
  • Side gear without hub
  • Fits Ford 8″ and 9″ Trac Loc positraction with 31 spline axles
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Motive Gear – Differential Pinion Shim Kit (Part No.WAA4663)

Differential Pinion Shim Kit

from

$15.99
All Motive Gear products are engineered for their specific application and manufactured in state of the art facilities. All of our products undergo rigid quality control processes to insure proper fit, performance and longevity. Motive Gear products can be found in the winners circle at NHRA, IHRA, NMRA, NMCA, SODA, SCORE, BITD, Ultra-4 and NASCAR events because we offer unmatched selection and quality demanded by racers and their crew chiefs – the same quality and selection demanded by DIY customers and top mechanics. With four warehouses strategically located across North America, most Motive Gear orders arrive within 2-4 days. Win with Motive Gear!
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Yukon Gear – Outer Oil Slinger For Ford 7.5", 8.8", 9", 10.25" (Part No.33022)

Outer Oil Slinger For Ford 7.5", 8.8", 9", 10.25"

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$8.99
Replacement outer oil slinger for Ford 7.5″, 8.8″, 9″, 10.25″, Nissan Titan rear, Dana 44 Rubicon & 44 JK non-Rubicon.

Product Features:
  • Outer oil slinger for Ford 10.25″, 7.5″, 8.8″ and 9″ also Jeep JK and Nissan Titan rear
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Yukon Gear – Trac Loc Positraction, Ford 8.8", 31 Spline, With Carbon Fiber Clutches (Part No.20130)

Trac Loc Positraction, Ford 8.8", 31 Spline, With Carbon Fiber Clutches

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$774.99
Yukon Trac Loc positraction, Ford 8.8″, 31 spline, with Carbon Fiber clutches.

Product Features:
  • Trac Loc positraction carrier case
  • Includes spider gears
  • Fits Ford 8.8″ with 31 spline axles
  • Carbon fiber clutches
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Yukon Gear – Pinion Install Kit For Ford Daytona 9" Differential (Part No.13049)

Pinion Install Kit For Ford Daytona 9" Differential

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$225.99
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 Ford 9″ with Daytona pinion support
  • Included are pinion bearings and races, pinion seal, crush sleeve eliminator , complete pinion shim kit, and marking compound with brush.
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Yukon Gear – Adjuster Lock Bolt 3.062" & 3.250" Ford 9" Drop Out (Part No.32149)

Adjuster Lock Bolt 3.062" & 3.250" Ford 9" Drop Out

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$3.99
Adjuster lock bolt 3.062″ & 3.250″ Yukon Ford 9″ Drop Out.

Product Features:
  • Side adjuster lock bolt
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Yukon Gear – 3.062" Side Adjuster For Ford 9" (Part No.32139)

3.062" Side Adjuster For Ford 9"

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$94.99
3.062″ side adjuster, Only Fits Yukon Ford 9″ Drop Out, new design ONLY.

Product Features:
  • Side adjuster
  • Fits Ford 9″
  • 3.062″ designs only
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Yukon Gear – Pinion Gear And Thrust Washer For 8" And 9" Ford, Model 20, And 7.25" Chrysler (Part No.33301)

Pinion Gear And Thrust Washer For 8" And 9" Ford, Model 20, And 7.25" Chrysler

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$4.99
Pinion gear thrust washer for 8″ and 9″ Ford, Model 20, and 7.25″ Chrysler.

Product Features:
  • Pinion gear thrust washer for Ford 8″, Ford 9″ and Chrysler 7.25″
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Yukon Gear – 8" Ford O-Ring (Part No.30027)

8" Ford O-Ring

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$9.99
8″ Ford O-ring.

Product Features:
  • Pinion support o-ring
  • Fits Ford 8″
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Yukon Gear – Ford 8" & 9" Standard Open, Ag, & Detroit Locker Ring Gear Bolt (Part No.33043)

Ford 8" & 9" Standard Open, Ag, & Detroit Locker Ring Gear Bolt

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$5.99
Ford 8″ & 9″ standard Open, AG, & Detroit locker ring gear bolt, 1.0″ long, Ford.

Product Features:
  • Ring gear bolt for Ford 8″ and 9″
  • For use with standard open carrier, Auburn Gear limited slip and Detroit Locker
  • 1.0″ long
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Motive Gear – Differential Carrier Shim Kit (Part No.1101)

Differential Carrier Shim Kit

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$8.49
High-quality Differential Carrier Shim Kit

Product Features:
  • CARRIER SHIMS 12 BOLT GM CAR & TRUCK ALSO GM8.6″ 99-ON
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Yukon Gear – Star Washers, 3.250" Ford 9" Drop Out New Design Only (Part No.32144)

Star Washers, 3.250" Ford 9" Drop Out New Design Only

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$4.99
STAR washers, 3.250″ Yukon Ford 9″ Drop Out new design ONLY.

Product Features:
  • Star washer
  • Fits Ford 9″
  • 3.250″ designs only
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1978 Mercury Cougar Differentials

Maybe you’re in the middle of a full rebuild of that 1978 Mercury Cougar. Maybe you just need a couple of Differentials. Either way, Advance Auto Parts has 330 different Differentials in our inventory ranging from $1.99 to $1,566.99. That means you can find the exact parts or products you need to keep that 1978 Mercury Cougar running smoothly.

Differentials are only as good as their brand. We stock 12 different brands to make sure you have plenty of trusted parts to choose from for your 1978 Mercury Cougar. Yukon Gear, Dorman, and FELPRO are just some of the brands we stock. Search for brands you know or compare prices and reviews to help you decide!

We know you’ll find the perfect Differentials for your 1978 Mercury Cougar, but don’t take our word for it – read our customer ratings and reviews and buy with confidence. Out of the 96 reviews in this category, some of the top rated parts include Lock Right Locker with 5.0 stars and No-Slip Traction System with 5.0 stars.

So if you’re in the market for aftermarket Differentials to keep your 1978 Mercury Cougar rolling for years to come, look no further. Shop online and have your products shipped direct to your door, or pick up at the nearest Advance Auto Parts location today!

Differentials Brands To Make Your 1978 Mercury Cougar Last

Simple repair, complete replacement, or a full rebuild. No matter the job, your 1978 Mercury Cougar demands trusted brand parts and products to keep it running. Many trusted brands of Differentials make up Advance Auto Parts’ inventory, and all are ready to help make your Cougar the best it can be. Be sure to browse some of our top Differentials brands and parts.

Popular Felpro Differentials

We carry Felpro parts in our stock across Automatic Transmission Differential Cover Gaskets categories, plus more. For a 1978 Mercury Cougar, our most popular Felpro Differentials include:
Differential Carrier Gasket
from $8.49
(9)
Differential Carrier Gasket
Automatic Transmission Differential Cover Gaskets

FAQs for 1978 Mercury Cougar Differentials

What are the most purchased Differentials for the 1978 Mercury Cougar?

Out of 330 Differentials for the 1978 Mercury Cougar, the most popular in our inventory are:
3 Qt - 80W90 Conventional Gear Oil With Posi Additive
from $57.99
This product is not rated
3 Qt – 80W90 Conventional Gear Oil With Posi Additive
Differential Oil
Pinion Crush Sleeves
from $5.99
This product is not rated
Pinion Crush Sleeves
Differential Crush Sleeves
Multi Purpose Seal
from $15.79
(3)
Multi Purpose Seal
Differential Pinion Seals

What are the top-rated 1978 Mercury Cougar Differentials?

Top-rated Differentials for your 1978 Mercury Cougar based on customer reviews/ratings are:
Lock Right Locker
from $444.99
(1)
Lock Right Locker
“Fast service and the right part.”
No-Slip Traction System
from $551.99
(1)
No-Slip Traction System
“Installed, no issues, works great.”
Differential Pinion Nut
from $6.49
(1)
Differential Pinion Nut
“If a pinion nut is ever removed from the pinion shaft, it is recommended NOT to reuse it. Replace it with a BRAND NEW nut, even if the old nut is rel”