1978 GMC G25 Transmission Parts

Essential 1978 GMC G25 Transmission Parts

B & M – Kickdown Switch Kit For TH400 Transmission (Part No.20297)

Kickdown Switch Kit For TH400 Transmission

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$84.99
When swapping the TH400 transmission into any vehicle, this kit makes installation of the transmission’s kickdown feature a snap. This switch mounts to either a TH700R4, TH200, TH200-R4 or TH350 throttle cable bracket.

Product Features:
  • Allows High Speed Cruise
  • Cruise In Overdrive
  • Prevents Part Throttle Kickdown
  • Quick Installation
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Imperial – Maxi-Kool® XL Transmission Oil Cooler (Part No.243007)

Maxi-Kool® XL Transmission Oil Cooler

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$73.99
The Imperial Maxi-Cool® XL’s plate and fin design offer excellent cooling efficiency in a compact, space-efficient design.

Product Features:
  • Imperial Maxi-Cool® plate and fin transmission cooler
  • Size: 3/4″ x 11″ x 7-1/2″
  • Mid-size and full-size cars, pickups
  • GVWR up to 20,000 lbs.; towing up to 2,500 lbs.
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Mr. Gasket – Chrome Automatic Transmission Dipstick & Tube – 27" Length (Part No.9764)

Chrome Automatic Transmission Dipstick & Tube - 27" Length

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$30.99
Includes dipstick with chromed steel handle and chromed steel dipstick tube with mounting tab. 27 inch long.

Product Features:
  • Fits GM Th350 – Chevy Specific. Modify For Others
  • 27 In Length
  • Chrome Plated Steel
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ATP – AT SEL SHAFT SEAL (Part No.SO-19)

AT SEL SHAFT SEAL

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$7.99
AT SEL SHAFT SEAL

ATP – Automatic Transmission Detent Cable (Part No.Y-103)

Automatic Transmission Detent Cable

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$29.99
Detent cables connect the throttle mechanism to the transmission. Old cables can bind, break, or just become sluggish. The best repair is to replace the old cable with a new one. ATP Detent cables are designed to fit and function just like the original part to ensure durability and long life.

Product Features:
  • Includes brackets, grommets, etc to match original
  • Helps transmission determine ideal downshift
  • Improves vehicle performance
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Edelbrock – Automatic Trans Cable Adapter #8026 for GM 2004R, 700R4, 4L60 Transmissions (Part No.8026)

Automatic Trans Cable Adapter #8026 for GM 2004R, 700R4, 4L60 Transmissions

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$18.99
Product Features:
  • Edelbrock Part # 8026 GM Transmission adapter is for use with 2004R, 700R4, 4L60 transmissions.
  • This kit relocates the pin position on an Edelbrock Carburetor when hooking up to a throttle valve style transmission (700R4, 2004R, 4L60).
  • The pin location is critical as the TV controls line pressure, shift points, shift firmness, and part throttle downshifts.
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B & M – Cable Bracket (Part No.30498)

Cable Bracket

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$28.99
Cable Bracket, GM (Bandit style shifters only) APPLICATION: For TH-400, 350, 250, 200, 700R4, 200-4R with 80797, 80798 or 81050 shifter.

Product Features:
  • Shifter Service Parts
  • Steel
  • Natural Finish
  • Sold individually
  • Replacement for Bandit shifters
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National – Multi Purpose Seal (Part No.8792S)

Multi Purpose Seal

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$6.99
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.

Product Features:
  • Low swell in hydrocarbon fluids
  • Design type: spring loaded; multi-lip
  • Provides good low temperature capability
  • Temperature range: -40°F to 225°F; -40°C to 107°C
  • Delivers quality and reliable performance for every type of repair
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B & M – Governor Recalibration Kit For TH-700R4, TH-400 and TH-350 Transmission (Part No.20248)

Governor Recalibration Kit For TH-700R4, TH-400 and TH-350 Transmission

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$109.99
This kit allows you to adjust the shift points of your transmission after it is installed in your vehicle. The Governor Recalibration Kit is very useful if you have a vehicle that is very light; has a low rear-end gear ratio.

Product Features:
  • Adjust Shift Points Of Transmission
  • Useful For Light Vehicles
  • For Low Rear End Gear Ratio
  • Or Useful If It Is Conversion
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B & M – Shift Improver Kit For 68-81 TH-350 Transmission (Part No.30262)

Shift Improver Kit For 68-81 TH-350 Transmission

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$62.99
HEAVY DUTY-Firm positive shifts without loss of driver comfort for improved performance in all street vehicles. STREET/STRIP-Positive shifts for high performance street use or for competitive events. Hardest, quickest possible shift.

Product Features:
  • Provides Crisp Shifts
  • On Any Stock Automatic Transmission
  • Eliminates Soft/Sluggish Shift
  • Eliminates Shift Overlap
  • Eliminate Clutch and Band Wear
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B & M – Master Overhaul Kit For Powerglide Transmission (Part No.21040)

Master Overhaul Kit For Powerglide Transmission

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$399.99
The B&M Master Racing Overhaul Kit includes all gaskets, seals, bushings and high performance friction materials. No transbrake body gaskets or instructions included.

Product Features:
  • Complete High Perf. Or Racing Trans. Overhaul
  • Includes Only OEM Valvebody Gaskets
  • Instructions Not Included
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ATP – AT DPSTK TUBE SEAL (Part No.SO-35)

AT DPSTK TUBE SEAL

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$5.99
AT DPSTK TUBE SEAL

ATP – AT FRT PUMP BUSHING (Part No.CB-4)

AT FRT PUMP BUSHING

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$10.99
AT FRT PUMP BUSHING

National – Cylindrical Bearing (Part No.5707)

Cylindrical Bearing

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$22.99
Manufactured with premium-grade steel, National® cylindrical bearings are designed and engineered to meet OE specifications.

Product Features:
  • Premium bearing design matches OEM specifications
  • Precision manufactured using premium-grade steel for outstanding durability and performance
  • Controlled heat treating process for lasting performance and extended bearing life
  • Industry leading coverage
  • Professional technicians know they can depend on National
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ATP – AT DETENT CABLE SEAL (Part No.SO-36)

AT DETENT CABLE SEAL

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$3.99
AT DETENT CABLE SEAL

Driveworks – Auto Transmission Shift Shaft Seal (Part No.S-8792S)

Auto Transmission Shift Shaft Seal

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$2.49
Product Features:
  • Brand may vary by location
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National – Bearings (Part No.A-3)

Bearings

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$14.99
National Oil Seals & Bearings offer a full line of premium oil seals and bearings.

Product Features:
  • Premium bearing design matches OEM specifications
  • Precision manufactured using premium-grade steel for outstanding durability and performance
  • Crowned raceways and rollers to ensure even load distribution for maximum life
  • Industry leading coverage
  • Professional technicians know they can depend on National
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ATP – AT SHF LINK BUSHING (Part No.JO-119)

AT SHF LINK BUSHING

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$3.99
AT SHF LINK BUSHING

Driveworks – Taper Bearing Cup (Part No.S-M-88010)

Taper Bearing Cup

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$5.29
Value-priced bearing meets all cataloged application requirements.

Product Features:
  • Brand may vary by location
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Anchor – Transmission Mount: Rear, 1 Piece (Part No.2268)

Transmission Mount: Rear, 1 Piece

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$8.29
The purpose of the mount is to support the engine and transmission on the chassis and dampen vibration and noise from reverberating to the rest of the vehicle. Engine and Transmission Mounts are engineered and manufactured to meet or exceed OEM specifications using the latest CAD/CAM engineering process to ensure superior quality, form, fit and function. Only premium quality materials are used in the manufacturing process to guarantee precise performance and maximum durability. Applicable to BUIC 66-73; CHEV 58-84; GMC 67-84; OLDS 68-72; PONT 61-77;. Please verify your application.

Product Features:
  • MAXIMUM LIFE & PERFORMANCE: Both natural and SBR (Styrene Butadiene) rubber provide good abrasion resistance and aging stability to ensure maximum life and performance.
  • MEETS OR EXCEEDS DUROMETER MEASUREMENTS: All rubber material is manufactured to specific Durometer (hardness) measurements based on the vehicle’s application requirements.
  • HARDENED STEEL FASTENERS: All fasteners are made of hardened steel with heat treated Grade #5 bolts.
  • SUPERIOR BOND: A special Chemlock® bonding agent is used to ensure a superior rubber-to-metal bond.
  • HYDRAULIC MOUNT DESIGN: Hydraulic Mounts (applicable where OE) are designed for most front wheel drive vehicles because transverse drive train mounting.
  • For Years: 1958-1984
  • Weight approx: 2 Lbs
  • RUBBER CROWN WITH AIR GAP
  • HEIGHT WITHOUT STUDS: 1.9 INCH: 48.25 MM
  • STUDS AND BOLT HOLES INLINE
  • STUD CENTERLINE: 1.5 INCH: 38.1 MM
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National – Multi Purpose Seal (Part No.5208)

Multi Purpose Seal

from

$18.29
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.

Product Features:
  • Low swell in hydrocarbon fluids
  • Design type: spring loaded; multi-lip
  • Provides good low temperature capability
  • Temperature range: -40°F to 225°F; -40°C to 107°C
  • Delivers quality and reliable performance for every type of repair
See More

B & M – Automatic Shifter, Megashifter-Right Hand Drive (Part No.80685)

Automatic Shifter, Megashifter-Right Hand Drive

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$469.99
The B&M Megashifter has it all, form, function and classic style. This all adds up to bring you a quality shifter that’s been one of the most popular automatic shifters of all time. The light truck Megashifter is better suited for truck and bench seat app

Product Features:
  • Universal Floor Mount Application
  • Cable Operated
  • Quick Installation
  • Accurate Shifting
  • NHRA/IHRA Reverse Lockout Meets Requirements
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Felpro – Manual Transmission Gasket Set (Part No.TS 30118)

Manual Transmission Gasket Set

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$24.49
Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered and manufactured specifically for the repair environment
  • Unsurpassed quality you can trust
  • Includes all parts needed to complete the repair
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Felpro – Manual Transmission Gasket Set (Part No.TS 80108)

Manual Transmission Gasket Set

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$9.29
Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered and manufactured specifically for the repair environment
  • Unsurpassed quality you can trust
  • Includes all parts needed to complete the repair
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ARP Auto Racing – For Use With 90 Degree V6 Chevy/ 265 And 454 V8 With 2 Piece Rear Seal (Part No.200-2902)

For Use With 90 Degree V6 Chevy/ 265 And 454 V8 With 2 Piece Rear Seal

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$19.79
Flywheel and flex plate bolts play an important role in the performance and safety of race cars and street machines alike. That is why the fastener experts at ARP have developed special bolts that are far superior to OEM hardware. ARP offers two styles of flywheel/flex plate bolts: High Performance and Pro Series. They are both forged from aerospace alloy and heat treated prior to thread rolling and machining. Both feature an exclusive, flat, 12 point head design and larger than stock shank diameter for increased strength and improved flywheel register. The popular High Performance series is rated at 180,000 PSI, and the premium grade Pro Series, originally developed for NASCAR competition, has a 200,000 PSI rating. Complete with washers and nuts where applicable.

Product Features:
  • Forged From Aerospace Alloy And Heat Treated Prior To Thread Rolling And Machining
  • Feature An Exclusive, Flat, 12 Point Head Design And Larger Than Stock Shank Diameter
  • Flanged Nut
  • Increased Strength And Improved Flywheel Register
  • Chevy 90░ V6 & 265-454 With 2-pc Rear Seal, Ford 289-460
  • 0.68″ Underhead Length
  • 200,000 PSI
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ARP Auto Racing – For Use With 90 Degree V6 Chevy/ 305, 502 V8 With 1 Piece Rear Seal (Part No.200-2906)

For Use With 90 Degree V6 Chevy/ 305, 502 V8 With 1 Piece Rear Seal

from

$18.99
Flywheel and flex plate bolts play an important role in the performance and safety of race cars and street machines alike. That is why the fastener experts at ARP have developed special bolts that are far superior to OEM hardware. ARP offers two styles of flywheel/flex plate bolts: High Performance and Pro Series. They are both forged from aerospace alloy and heat treated prior to thread rolling and machining. Both feature an exclusive, flat, 12 point head design and larger than stock shank diameter for increased strength and improved flywheel register. The popular High Performance series is rated at 180,000 PSI, and the premium grade Pro Series, originally developed for NASCAR competition, has a 200,000 PSI rating. Complete with washers and nuts where applicable.

Product Features:
  • Forged From Aerospace Alloy And Heat Treated Prior To Thread Rolling And Machining
  • Feature An Exclusive, Flat, 12 Point Head Design And Larger Than Stock Shank Diameter
  • Flanged Nut
  • Increased Strength And Improved Flywheel Register
  • Chevy 90░ V6 & 305-502 With 1-pc Rear Seal
  • 0.725″ Underhead Length
  • 200,000 PSI
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B & M – Transmission Accessories, Converter Lockup Controller (Part No.70244)

Transmission Accessories, Converter Lockup Controller

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$309.99
The B&M converter lockup controller provides dash-mounted control to govern converter lockup at any speed between 30 and 90 mph. These kits eliminate converter lock and unlock cycling and premature unwanted converter lockup.

Product Features:
  • Dash Mounted Control For Speeds Between 30-90 mph
  • LED Indicates Locked OR Unlocked
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Popular 1978 GMC G25 Transmission Parts Categories

1978 GMC G25 Transmission Parts

You count on your 1978 GMC G25 to run right. That means taking care of it with regular maintenance, necessary repairs, and the right parts. Advance Auto Parts can help with all of that thanks to our extensive inventory of trusted Transmission Parts. With 145 Transmission Parts ranging in price from $1.99 to $1,150.00, you’re sure to find everything you need for your 1978 GMC G25.

Brands matter. If you want to shop a specific Transmission Parts brand, we stock 16 different brands like National, Imperial, and Driveworks. 1978 GMC G25 Transmission Parts start as low as $1.99!

One of the best ways to find top quality OEM or aftermarket Transmission Parts is by asking professionals. Short of that, you can shop with confidence thanks to our 1,908 extensive product reviews on 1978 GMC G25 Transmission Parts. Some of the top-rated Transmission Parts products we carry are Multi Purpose Seal with 4.4 stars and Automatic Shifter, Z-Gate with 4.4 stars.

Did we mention you can order your Transmission Parts from our online catalog and have them shipped right to your garage? Or, if you feel like seeing the parts first-hand, search for your nearest Advance Auto Parts location above and pick up in-store when you’re ready. Browse our full Transmission Parts inventory for your 1978 GMC G25 below to get started!

Top-Rated Transmission Parts Brands For Your 1978 GMC G25

Trusted Transmission Parts OEM and aftermarket product brands are what Advance Auto Parts specializes in. The brands we work with are sure to keep that 1978 GMC G25 running right for years to come. In our inventory you’ll find brands like National, Imperial, Driveworks, and even more.

Popular Felpro Transmission Parts

You’ll find popular Felpro brand products across Automatic Transmission Pan and Gaskets. All are waiting to get your 1978 GMC G25 back on the road. Some of the top-rated Felpro products in these categories are:
Transmission Oil Pan Gasket
from $8.49
(3)
Transmission Oil Pan Gasket
Transmission Oil Pan Gaskets
Transmission Oil Pan Gasket
from $9.29
(5)
Transmission Oil Pan Gasket
Transmission Oil Pan Gaskets

FAQs for 1978 GMC G25 Transmission Parts

What are the most purchased Transmission Parts for the 1978 GMC G25?

Out of 145 Transmission Parts for the 1978 GMC G25, the most popular in our inventory are:
Bearings
from $14.99
(21)
Bearings
Miscellaneous Transmission Bearings
Cylindrical Bearing
from $22.99
(20)
Cylindrical Bearing
Axle Output Shaft Bearings
High-Torque, High-Vibration RTV Silicone Gasket Maker, 13 OZ
from $26.99
(7)
High-Torque, High-Vibration RTV Silicone Gasket Maker, 13 OZ
Transmission Pan Gaskets

What are the top-rated 1978 GMC G25 Transmission Parts?

Top-rated Transmission Parts for your 1978 GMC G25 based on customer reviews/ratings are:
Multi Purpose Seal
from $6.99
(20)
Multi Purpose Seal
“The product works well”
Automatic Shifter, Z-Gate
from $279.99
(11)
Automatic Shifter, Z-Gate
“Good Product, Great For The Price”
Automatic Transmission Vacuum Modulator
from $34.49
(11)
Automatic Transmission Vacuum Modulator
“worked”