The arrival of the 1978 Chevy Corvette would happen just a few months after the 500,000th model rolled off the St. Louis assembly line (see the “1977 Corvette Overview” for further detail). As significant as that milestone had been as a benchmark of Corvette’s success, the 1978 model would mark a second milestone – Corvette’s Silver Anniversary.
Just as the Corvette had been America’s only true production sports car in 1953, the 1978 Corvette continued to carry that mantle 25 years later, and with similar distinction.
Despite being a dramatically different – and far more challenging – automotive market than the one that had existed when Harley Earl‘s prototype first graced General MotorsMotorama in New York City, the 25th Anniversary Corvette would still enable General Motors to commemorate the anniversary with class.
There were, of course, concessions that had been made by automotive manufacturers both in the United States and around the world. Sports cars as a whole had become a dwindling commodity. With each passing year, manufacturers had to deal with a broader (and ever growing) array of political, environmental, and financial challenges that made building expensive sports cars increasingly impractical.
The oil embargo of 1973 – 1974 had caused consumers to shun the gas-guzzler automobiles that had been popular just a decade earlier. Instead, the big sales winners were fuel efficient cars like those being built by the Japanese.
What made that even more desirable was that, in addition to being good on gas, they were far more dependable than most of the automobiles being built in the United States. In addition to fuel costs, higher insurance premiums, increased engineering requirements to further regulate engine emissions, and subsequently, higher car prices themselves made buying new cars less and less practical.
Still, General Motors had recognized that the Chevy Corvette was indispensable as a high-profit personal car that doubled as a showcar that got spectators into the automobile showrooms. They recognized that Corvette owner loyalty was fiercer than it had ever been. As such, they saw no need to re-vamp the current Corvette design, especially when the current car was still selling at or near its all-time-high volume.
Additionally, General Motors recognized that there were many other models in their automobile portfolio that needed to be reworked to survive the rising costs throughout the entire automobile industry. As such, a new, fourth-generation Corvette would not be seriously considered for several more years, though the idea of updating (or even replacing) the current model was not completely forgotten.
While work towards a new front-engine Corvette got underway during Corvette’s 25th year, no timetable was attached to the completion of the new model.
Instead, to celebrate 25 years, executives within Chevrolet decided that something special had to be done to the current Corvette to commemorate the car’s silver anniversary. The question that followed this decision was this: how could Chevrolet make a notable modification to the current model on a very limited budget? The answer was simple: trim away the old “flying buttress” sail panels and substitute a large, compound curved rear window. In so doing, Chevrolet engineers not only gave the aging third-generation Corvette a new look, but they also brought about the return of the Corvette fastback, which had been notably absent since 1967.
DID YOU KNOW: While the 1978 Corvette Pace Car Replica is arguably one of the most popular examples of the C3 Corvette, its original design was very different from the car that everyone knows today. In the design phase, the original Pace Car design was to feature a two-tone silver paint with red striping, and was to feature special Goodyear tires with the word “CORVETTE” imprinted in raised, white, sidewall lettering. Additionally, only 300 of these collector Pace Cars were going to be produced in commemoration of the original 300 Corvettes built in 1953.
While a lot of discussion had centered around making the rear window a hinged, lift-up hatchback design, Dave McLellan, Chief Engineer of the Corvette, opted not to complicate the design for the 1978 model (though he would later introduce the option as part of the Collector Edition Hatchback model in 1982.)
Though not a hatchback, the addition of a curved window to the C3 not only improved the car’s overall appearance, it enhanced rearward visibility while also providing nearly three times the available luggage room of earlier models and greater ease of access. A retracting cover was also added to the rear compartment to offer added security and protection from the sun.
In addition to the new rear window, Chevrolet also felt that the 1978 model warranted a special “25th Anniversary” package to commemorate the car’s silver anniversary. Bill Mitchell had suggested a Silver Anniversary model in his favorite color – silver (which seemed appropriate) – and so it was decided that the 1978 “25th Anniversary Corvette” would indeed include a silver paint scheme.
Additionally, the car received a special striping package. Though inexpensive to manufacture, the striping package would be viewed by many consumers as a desirable package and, as such, GM would be able to mark up the package considerably. Ultimately, the “25th Anniversary” paint scheme ended up being two-tone; silver over a gray lower body with a separating pinstripe.
Listed as RPO B2Z, the special paint package cost an additional $399 over the base price of the car. It was also the first factory optioned two-tone Corvette offered since 1961. The anniversary car also received special “Silver Anniversary” badges, aluminum wheels, and dual “sport” outside mirrors as mandatory options, which added another $380 to the total cost of the car.
To further commemorate Corvette’s 25th anniversary, Chevrolet had negotiated with the Indianapolis Motor Speedway to allow a modified Corvette to serve as the pace car for the 1978 running of the Indianapolis 500.
The car, much like the Silver Anniversary Edition, featured a special, two-tone paint scheme, although for this model, the color choice was black over silver metallic with a bright red pinstripe between the two tones of paint.
The Corvette Indy Pace Car also featured a front and rear spoiler, both of which added a more dramatic appearance to the car, though neither offered much in the way of additional downforce (or other functionality.) The front spoiler was similar to the one installed on the 1978 Pontiac Trans Am. It wrapped under and around the front of the car, blending into the wheel wells. The rear spoiler, on the other hand, curved down at its outbored ends to meet the bodysides of the Corvette.
The interior of the Corvette Pace Car was directly influenced by Bill Mitchell and featured either full silver leather or leather/gray cloth upholstery and gray carpeting. Chevrolet introduced a new, thin-shell seat design that featured more lumbar support. Although these seats were originally slated for the 1979 model, the development program was accelerated so that these new seats could be introduced as part of the 1978 Pace Car package.
Naturally, development of a special Corvette Pace Car meant an opportunity to market the design to consumers. Chevrolet initially decided that they would produce 2,500 Indy 500 Pace Car replicas or 100 cars for each year of Corvette’s production since 1953. Each of these cars would be sold on a “first come, first serve” basis.
However, as Chevrolet already had 6,200 established dealerships at the time, it was quickly decided that a minimum order of 6,200 units should be built so that each showroom could have at least one. As such, the “Limited Edition Indy Pace Car Replica” Corvette actually accounted for 15 percent of all the Corvettes manufactured that year.
Like the Silver Anniversary model, the Pace Car Replica was actually offered to consumers as an option package – RPO Z78. Like the actual pace car, it featured the same black over silver paint scheme, the same pin striping and spoiler kit, and the same interior.
Additionally, all the replicas included the new glass T-tops, alloy wheels, power windows, rear window defogger, air conditioning, sports mirrors, tilt/telescopic steering wheel, a heavy duty battery, an AM/FM stereo equipped with either an eight-track tape player or a CB radio, and power door locks. In addition to these features, each Indy Pace Car Corvette replica owner would receive a set of regalia decals that they could install at their discretion. The decal set included the famous “winged wheel” Indy Speedway logos for the rear fenders, as well as large door emblems that read “Official Pace Car, 62nd Annual Indianapolis 500 Mile Race, May 28, 1978.”
Of course, all of the 1978 Corvettes received other updates as well. While a lot of time and attention had been given to the two special edition cars, all Corvettes would undergo a series of cosmetic and functional updates that would make the newest entry unique, regardless of which package prospective consumers ultimately purchased.
All 1978 Corvettes received special “Silver Anniversary” badging on the exterior of the car. The interior received far more attention. The speedometer and tachometer were now encased in squared-up instrument panel housings, matching the previous year’s revamped console gauges. A genuine glovebox was added.
The interior door panels featured an all-new design with armrests that were screwed onto the door instead of being molded into the door as they had been since 1965. The doors now also featured integral door pulls. A single piece, fully padded dashboard with a front mounted cluster was developed for easier removal in such cases where service was required. Windshield and wiper controls were moved back to the instrument panel, but the dimmer switch remained on the steering column. The three-point seat belts were given a single inertia reel, and belt guides were eliminated.
All of the 1978 Corvettes also featured an updated anti-theft system. The new security system, which was installed as a standard option on all Corvettes, was modified from previous years to include activation in the event that the T-tops were to be tampered with in any way. As the T-tops were a valuable item to car thieves, this additional security proved most valuable, as the 1978 Corvette was identified by law enforcement that year as one of the most frequently stolen cars.
Glass T-tops were offered for the first time in 1978, though GM had originally intended for them to be available on the 1977 model. Both the glass tops and the normal fiberglass T-top panels were modified to provide additional headroom to both the driver and passenger, and both included a key-lock assembly that helped further secure them to the vehicle by securing each T-top latch from being operable when locked.
Mechanically, the car remained very similar to the 1977 Corvette that had come before it. A few changes were made, including a larger fuel tank, which now held 24 gallons of gas (versus the 17 gallon tank used on the previous year.) The tank itself features an internal molded plastic liner cased inside of a steel shell. To accommodate the larger fuel tank, Corvette introduced a smaller, lighter weight spare tire. Wider 60-series tires were also introduced on the 1978 Corvette as an option, and the installation of these would require fender trimming at the Corvette assembly path to ensure proper fit. The tires, manufactured by Goodyear, were sized at 225/60R-15’s. Aramid-belt construction in the tires contributed to a claimed improvement in ride smoothness.
Power ratings diminished some as a result of stricter emission standards, and also as a result of the government’s new Corporate Average Fuel Economy (CAFÉ) mandates that took effect that year. As with the 1977 Corvette it, the 1978 model featured two basic versions of the 350 CI small-block V-8 engine from which consumers could choose. The base L48 produced 185 brake horsepower in every state except California. For California and high-altitude areas, the engine generated 175 bhp. For consumers looking for a car with some additional power, the optional L82 engine could be purchased for an extra $525. The L82 featured an output of 220 brake horsepower via a dual-snorkel air intake system which allowed the delivery of a larger volume of cool air into the engine while a revamped exhaust system that featured larger exhaust and tailpipes along with lower restriction mufflers had been designed to reduce back pressure.
A close-ratio four-speed manual transmission returned as an exclusive option for the L82 engine, and a 3.70:1 rear axle made this combination the best performing setup available to consumers that year. The same gearset was also offered for the L82 with the wide-ratio four-speed transmission, while the L48 engine came with a 3.36:1 axle (which was also available on the L82 with the wide-ratio setup.) Additionally, the L82 was offered with a revised Turbo Hydra-Matic that featured a low-inertia, high-stall-speed (2,400rpm) torque converter. Corvettes equipped with the automatic transmission featured a 3.55:1 final drive, with the exception of the L48 at high altitudes, where the ratio was 3.08:1.
The FE7 Gymkhana Suspension package was again available for the 1978 Corvette, though its price had increased considerably from its original $7.00 price-tag in 1974. Now selling for an additional $41.00, the suspension package included heavy-duty shocks and higher-rate springs for all four wheels, plus a rear anti-roll bar and a thicker front stabilizer bar.
The arrival of the 1978 Corvette was met with a great deal of praise, especially for its more refined ride and appearance, both of which seemed to revitalize the car in the public eye.
The addition of the larger wrap around rear window earned the car praise, especially from reviewers like Car & Driver who stated “the large rear window freshened up the Corvette’s profile, and it also added space and light to help relieve the claustrophobia inside this, the most tightly coupled car known to man.”
Automobile critics praised the car’s performance aspects too – especially those Corvettes equipped with the L48 engine/automatic transmission combinations. When so equipped, the Corvette boasted 0-60mph times of just 7.8 seconds and a top speed of 123 miles per hour.
At the same time, critics were also quick to point out that the Corvette’s cockpit continued to feel cramped and uncomfortable, and that the car’s front to rear axle weight distribution was uneven, causing the back end of the car to “step out” during sharp cornering maneuvers.
Still, the 1978 Corvette sold quite well, moving 46,776 units in all. Of these, 6,502 sold were the limited edition Corvette Pace Car model, which retailed for more than $4,000 over the standard model. While the base coupe started at $9,351.00, the Pace Car had a sticker price of $13,653.21. Still, the Pace car had a unique “collector’s quality” about it which made it extremely desirable to consumers – so much so that every Pace Car in 1978 sold for more than list price.
The Pace Car look was so popular that it actually tempted some owners of the standard 1978 Corvette coupes to create a “clone” that they could pass off as the Pace Car model.
While many of these “clones” were very convincing, there were (and still are for those consumers looking to buy one) some key indicators that helped spotters identify the real Pace Car replicas from the homemade knock-offs. For one, most counterfeiters would never replace the factory installed seats with the special edition seats used in the pace car. For another, the Pace Car edition Corvettes featured a special vehicle identification number (VIN).
The 1978 Corvette Pace Car VIN numbers had the number “9” as the eighth digit in the thirteen-digit sequence as opposed to the number “4” associated with all other 1978 models.
From a historical perspective, the 1978 Corvette Pace Car also set an important milestone when it paced the Indianapolis 500 that year. It represented the first time that an unmodified, truly stock machine paced the annual Memorial Day race. The Corvette that led the pack of drivers (which included Tom Sneva, Al Unser Jr., Rick Mears, along with 30 other drivers on May 28, 1978) was almost identical to the Pace Car replica which was sold to consumers that year, save for the two openings made in the back of the car for the required flag poles mounted on the actual pace car.
In all, the 1978 Corvette saw the resurgence of a car brand that had begun to falter some throughout the previous decade. Between the Silver Anniversary and Pace Car Limited Edition Corvettes, and the overall look and feel of the 1978 model as a whole, there was no doubt that Corvette was moving in a better direction once more.
As stated in Car & Driver Magazine, “After a number of recent Corvette editions that prompted us to mourn the steady decline of both performance and quality in this once-proud marquee, we can happily report the twenty-fifth example of the Corvette is much improved across the board.
Not only will it run faster now – the L82 version with four-speed is certainly the fastest American production car, while the base L48 automatic is no slouch – but the general drivability and road manners are of a high order as well.”
Uniconstruction: fiberglass reinforced plastic (FRP or “fiberglass”) body, backboned by a steel cage outlining the passenger compartment. Principal members – underbody, front and rear end assemblies, dash panel and hinge pillars are bonded, riveted, or bolted together and to each other. Hood is plastic with bonded plastic reinforcement. Coupe: two removable roof panels and removable rear window. Frame: all welded, full length, ladder construction with 5 crossmembers. Side Rails and intermediate crossmembers box section; front crossmember box girder section. Eight body-mounting points.
Type and Description: Independent, SLA type with coil springs with center mounted shock absorber.
Front Coil Springs
Make & Type
10.49 in. (coil height) x 3.80 in. (int.dia.); 133.83 in. (length) x .609 in. (dia. of coiled steel) *
295lbs. per inch *
Rate at Wheel
117.6lbs. per inch *
Front Stabilizer Bar
Hot rolled steel
Suspension – Back
Type and Description: Full Independent rear suspension with fixed differential; transverse. Multi-leaf spring, lateral struts and universally jointed axle shafts. Drive and torque taken through torque control arms.
Rear Leaf Springs
Number of Leafs
Chrome carbon steel
Length, width, height
48.60 in. (length) x 2.50 in. (width)
198 lbs. per inch *
Rate at Wheel
151 lbs. per inch *
Link (RPO FE7 Gymkhana Suspension Only)
Hot rolled steel
(*) For base equipped models, springs are computer selected by size and rate according to vehicle weight including optional equipment. Spring rates and shock absorber equipment may vary when engine, transmission or Gymkhana suspension options are used.
Caliper Disk – 4 Wheel Dual Hydraulic with Pressure Differential and Warning Light
Delco Moraine, vacuum power unit; integral
Vehicle Assembly Location. S – St. Louis, Missouri
4XXXXX (Eighth thru Thirteenth Digits)
Plant Sequence Numbers.
The last six digits for the Corvette Coupe begin at 400001 and run thru 440274, accounting for all 40,274 Corvette Coupes built in 1978. The last six digits for the Corvette Coupe Pace Car begin at 900001 and run thru 906502, accounting for all 6,502 Corvette Coupe Pace Cars built in 1978. Each Vehicle Identification Number (VIN) is unique to an individual car.
1978 Corvette Vehicle Serial Number Plate
For all 1978 Corvettes, the location of the Vehicle Identification Number (VIN) is stamped on a plate attached to the left front body hinge pillar.
1978 Corvette Body Number & Point Plate
On the driver’s side upper left-hand door hinge pillar.
H27 – Body build date code.
H – Designates the Month (See Chart Below).
A – Sep., 1977B – Oct., 1977C – Nov., 1977D – Dec., 1977E – Jan., 1978F – Feb., 1978, G – Mar., 1978H – Apr., 1978 I – May., 1978 J – Jun., 1978 K – Jul., 1978 L – Aug., 1978
27 – Designates the Day of the Month.
152 – Interior Trim code. 152 – Silver (Leather)
19U – Exterior Color Code Upper Half of Body. 19 – Black
47M – Exterior Color Code Lower Half of Body. 47 – Silver
1978 Corvette Factory Options
Base Corvette Sport Coupe
1YZ87 / 78
Limited Edition Corvette Pace Car
Power Door Locks
Silver Anniversary Paint
Removable Glass Roof Panels
Rear Window Defogger
Optional Rear Axle Ratios
350ci, 220hp Engine
4-Speed Manual Trans, Close Ratio
High-Altitude Emission Equipment
Tilt-Telescopic Steering Column
White Letter SBR Tires, P255 / 60R15
White Letter SBR Tires, P225 / 70R15
Heavy Duty Battery
AM-FM Radio, stereo with 8-track tape
AM-FM Radio, stereo with CB
AM-FM Radio, stereo
Dual Rear Speakers
California Emission Certification
Aluminum Wheels (4)
Base Corvette Sport Coupe (1YZ87)
The base price of the 1978 Chevrolet Corvette Coupe without any optional equipment.
A 350 cubic inch, 185 horsepower engine, 4-speed wide ratio manual transmission, leather interior trim, and T-tops were included in the base price.
Limited Edition Corvette Pace Car (1YZ87 / 78)
The base price of the 1978 Limited Edition Corvette Pace Car without any additional optional equipment.
A 350 cubic inch, 185 horsepower engine, 4-speed wide ratio manual transmission, power windows, power door locks, removable glass roof panels, rear window defogger, air conditioning, sport mirrors, tilt-telescopic steering column, white letter SBR tires
P255/60R15, heavy duty battery, AM-FM radio/stereo with 8-track tape, power antenna, dual rear speakers, aluminum wheels (red accent), convenience group and special seats were included in the base price.
A total of 6,502 Corvette Pace Car replicas were built.
Power Windows (A31)
Factory installed power driver and passenger windows.
Power Door Locks (AU3)
Factory installed power door locks.
Silver Anniversary Paint (B2Z)
A special Silver Anniversary paint option.
It includes a two-tone silver and gray paint treatment which accentuates body contours.
Removable Glass Roof Panels (CC1)
Tinted glass lift-out roof panels.
Rear Window Defogger (C49)
An optional rear window forced air defogger.
Air Conditioning (C60)
Factory installed four-season air-conditioning.
System includes evaporator, blower, condenser, receiver-dehydrator, refrigerant (freon) tank, air intake assembly and duct assembly for both systems. Includes an integrated heater.
Sport Mirrors (D35)
Outside mirror assembly that included a mechanical linkage to control movement from inside the cockpit.
Gymkhana Suspension (FE7)
An optional, heavier-duty suspension system for higher levels of performance.
The Gymkhana rear leaf springs contained 9 leafs, though the top leaf is very small. GM identifies the rear leaf springs as an 8-leaf spring.
Included a stiffer front sway bar and stiffer springs.
There were no restrictions on ordering this option – it could be ordered with any engine/transmission combination.
Optional Rear Axle Ratios (G95)
A selection of optional rear axle ratios.
In 1978, these included: 3.08 (Code OA), 3.36 (Code OK), 3.36 (Code OM), 3.55 (Code OH), and 3.70 (Code OJ
Speed Control (K30)
An early version of (what is commonly known today as) cruise control.
The speed control option required an automatic transmission.
350ci, 220hp Engine (L82)
Optional higher-output, small block V-8 engine.
4-Speed Manual Transmission, Close Ratio (M21)
A close ratio version of the M20 Muncie 4-speed manual transmission.
The gear ratios for the RPO M21 Close Ratio 4-Speed Manual Transmission are: 1st Gear – 2.43:1, 2nd Gear – 1.61:1, 3rd Gear – 1.23:1, 4th Gear – 1.0:1 (Direct).
M21 was a no-cost option but required the optional L82 engine.
Automatic Transmission (MX1)
An optional, three-speed automatic transmission.
The Automatic Transmission consisted of a 3-element hydraulic torque converter and compound planetary gear set. It was equipped with the following gear ratios: 1st Gear – 2.52:1, 2nd Gear – 1.52:1, and 3rd Gear – 1.00:1.
High Altitude Emission Equipment (NA6)
Alternate emission equipment installed for vehicles operating at high altitudes.
The high-altitude emission equipment was required for vehicle operation at +4,000 feet.
Tilt Telescopic Steering Column (N37)
An optional, adjustable steering column and tilt-angle adjustable steering wheel.
The Telescopic Steering Column changes the drivers distance from the steering wheel by literally telescoping the steering wheel closer to or further away from the vehicle operator.
A new steering column positioned the steering wheel two inches closer to the instrument panel to provide more of an “arms out” driving position, and easier entry and exit.
White Letter Steel Belted Radial Tires, P255/60R15 (QBS)
Standard size tires with special raised white lettering.
White Letter Steel Belted Radial Tires, P225/70R15 (QGR)
Optional size tires with special raised white lettering.
Heavy Duty Battery (UA1)
Optional, heavier-duty battery with increased cranking amps/capability.
AM-FM Radio, Stereo with 8-Track Tape (UM2)
The standard/stock radio equipped with an 8-Track Tape Player.
The radio received broadcast in FM 2-channel stereo, FM monaural, and AM monaural.
Includes 8-track tape deck.
AM-FM Radio, Stereo with CB (UP6)
The standard dealer installed stereo system equipped with a CB (citizen band) radio.
The radio received broadcast in FM 2-channel stereo, FM monaural, and AM monaural.
Full 40-channel Citizens Band radio.
CB mike is stowed on the center console.
AM-FM Radio, Stereo (U58)
A standard/stock dealer installed Corvette radio.
The radio received broadcast in FM 2-channel stereo, FM monaural, and AM monaural.
AM-FM Radio (U69)
A standard/stock dealer installed Corvette radio.
The radio receives broadcast in FM monaural, and AM monaural.
Power Antenna (U75)
A extendable/retractable antenna for the car stereo system.
The antenna, which is located on the rear deck that retracts and extends when the radio or ignition is powered off and on respectively.
The power antenna extends 31 inches.
Dual Rear Speakers (U81)
Dual rear auxiliary speakers.
California Emission Certification (YF5)
Provided higher emission restrictions to meet the California emission standards.
Aluminum Wheels (4) (YJ8)
Included four aluminum wheels and a conventional steel spare.
Trailer Package (ZN1)
Factory installed trailer package.
The trailer package included the Gymkhana Suspension, a higher-amp alternator and a heavy-duty radiator.
The hitch was the standard, factory installed hitch available in 1978
The hitch could support approximately 100 pounds of tongue weight.
Convenience Group (ZX2)
A group of convenience options available to consumers when purchasing a 1978 Corvette.
The ZX2 Convenience Group included the dome light delay, headlight warning buzzer, underhood light, low fuel warning light, interior courtesy lights, and the passenger side visor mirror.
New styling for the 1978 Corvette included a fastback roof line and a new wraparound rear glass which provided for greater visibility with 1,425 square inches of surface area compared with 293 square inches on the former model.
Completely restyled interior with larger and more accessible rear storage area. The rear storage area included a retractable security cover.
The wiper and washer control were moved from the steering column stalk to the instrument panel. Turn signal and headlight dimmer controls remained on the steering column.
A new, one-piece, fully padded instrument panel with front-mounted cluster was introduced. It can be removed more easily for service. Printed circuit boards were used for improved reliability.
The vehicle anti-theft alarm was extended to include activation when the roof panels are removed.
Special “25th Anniversary” emblems and a special “25th Anniversary” two-tone paint option RPO B2Z.
Featured an increased operating range with a 24-gallon fuel cell replacing the former 17 gallon unit. The new fuel cell featured a molded plastic inner liner in a steel container. Space for the larger cell was made available by the use and stowage of a new, lighter weight temporary spare tire.
The three-speed automatic transmission used with the optional 5.7 litre engine was lighter weight and had a low inertia, high stall torque converter for increased performance.
The rear axle ratio on cars equipped with both the high altitude (NA6) and California emissions (YF5) options was changed from 3.08 to 3.55:1 to give a better starting ratio during acceleration and better performance throughout the speed band.
1978 Corvette Recalls
Make: CHEVROLET Model: CORVETTE Model Year: 1978 Manufacturer: CARDONE INDUSTRIES, INC. Mfr’s Report Date: MAY 07, 2003 NHTSA CAMPAIGN ID Number: 03E032000 NHTSA Action Number: N/A Component: SERVICE BRAKES, AIR:DISC:CALIPER Potential Number of Units Affected: 15899
REMANUFACTURED REAR BRAKE CALIPERS, PART NOS. 18-7019, 18-7020, 16-7019, AND 16-7020, MANUFACTURED FROM FEBRUARY 1, 2002, TO APRIL, 25, 2003., AND FOR USE ON 1965 THRU 1982 CHEVROLET CORVETTES. THE SUBJECT BRAKE CALIPERS WERE MANUFACTURED USING IMPROPERLY MANUFACTURED PISTON SEALS. THESE SEALS ARE INTENDED TO PREVENT FLUID LEAKAGE BETWEEN THE CALIPER HOUSING AND THE PISTONS. THESE BRAKE CALIPERS ARE FOR USE ONLY ON 1965 THRU 1982 CHEVROLET CORVETTE VEHICLES. THIS RECALL DOES NOT INVOLVE GENERAL MOTORS CORPORATION OR ANY OF ITS PRODUCTS.
UNDER THESE CONDITIONS, THE VEHICLE OPERATOR MAY NOT BE ABLE TO STOP THE CAR, POSSIBLY RESULTING IN A VEHICLE CRASH.
CARDONE WILL NOTIFY ITS CUSTOMERS AND ALL UNSOLD INVENTORY WILL BE REPURCHASED AND WILL PROVIDE A FULL REFUND TO CUSTOMERS. OWNER NOTIFICATION IS EXPECTED TO BEGIN DURING MAY 2003. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CARDONE AT 215-912-3000.
ALSO, CUSTOMERS CAN CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION¿S AUTO SAFETY HOTLINE AT 1-888-DASH-2-DOT (1-888-327-4236).
Make: CHEVROLET Model: CORVETTE Model Year: 1978 Manufacturer: HONEYWELL INTERNATIONAL, INC. Mfr’s Report Date: OCT 19, 2007 NHTSA CAMPAIGN ID Number: 07E088000 NHTSA Action Number: N/A Component: EQUIPMENT Potential Number of Units Affected: 121,680
CERTAIN HONEYWELL FRAM RACING BRAND HP4 AND HP8 OIL FILTERS THAT WERE MANUFACTURED FROM MAY 25, 2006, THROUGH SEPTEMBER 14, 2007, AND SOLD FOR USE AS REPLACEMENT EQUIPMENT FOR VEHICLES LIST ABOVE. THE AFFECTED FILTERS ARE MARKED WITH A DATE CODE A61451 THROUGH A72571 SEQUENTIALLY. THE DATE CODE AND PART NUMBER APPEAR ON THE FILTER HOUSING. FRAM RACING HP4 AND HP8 OIL FILTERS NOT BEARING A DATE CODE IN THIS RANGE ARE NOT AFFECTED BY THIS RECALL. THE GASKET OF THE OIL FILTER BECOMES MORE PLIABLE UNDER HIGH TEMPERATURES AND PRESSURES.
THIS CONDITION MAY CAUSE INADEQUATE SEALING AND LOSS OF ENGINE OIL, POSSIBLY RESULTING IN A FIRE.
HONEYWELL WILL REPLACE THE AFFECTED OIL FILTERS FREE OF CHARGE. THE RECALL BEGAN DURING NOVEMBER 2007. OWNERS CAN CONTACT FRAM CUSTOMER SERVICE TOLL-FREE AT 1-800-890-2075.
CUSTOMERS MAY CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION’S VEHICLE SAFETY HOTLINE AT 1-888-327-4236 (TTY: 1-800-424-9153); OR GO TO HTTP://WWW.SAFERCAR.GOV.
1978 Corvette Service Bulletins
1978 Corvette Common Issues
1978 Corvette Maintenance Schedule
The time or mileage intervals indicated on this website are intended as a guide for establishing regular maintenance and lubrication periods. Sustained heavy duty or high speed driving, or driving under adverse conditions may require more frequent servicing.
Additional Maintenance and Lubrication
In addition to the items listed above, it is also recommended that the following items are inspected every 300 miles or 2 weeks, whichever comes first:
Check Tire Pressure
Check Battery Water Level
Check Oil Level In Engine
Remove air cleaner and block throttle and choke in wide open position. Hook up starter remote control cable and insert compression gauge firmly in spark plug port. Whenever the engine is cranked remotely at the starter, with a jumper cable or other means, the distributor primary lead must be disconnected from the negative post on the coil and the ignition switch must be in the “ON” position. Failure to do this will result in a damaged grounding circuit in the ignition switch.
Crank engine through at least four compression strokes to obtain highest possible reading. Check and record compression of each cylinder. If one or more cylinders reads low or uneven, inject about a tablespoon of engine oil on top of pistons in low reading cylinders (through spark plug port.) Crank engine several times and recheck compression. If compression comes up but does not necessarily reach normal, rings are worn. If compression does not improve, valves are burnt, sticking or not sealing properly. If two adjacent cylinders indicate low compression, the cause may be a head gasket leak between the cylinders. Engine coolant and/or oil in cylinders could result from this defect.
The adjustments described apply to all carburetors used, except as noted. All adjustments are made with the engine at normal operating temperature.
Idle Speed (1977-1979)
See emission label on vehicle. Set engine for adjustments. Set ignition timing. For carburetors without solenoid and with air conditioner off, turn idle speed screw to set curb idle speed to specifications. For carburetors with solenoid, energize the solenoid, disconnect the air conditioner at the compressor, turn air condition on, set A/T in drive, M/T in neutral and turn solenoid screw to adjust speed to specified RPM.
Idle Mixture (1977-1979)
Idle mixture screws have been preset at the factory and capped. Do not remove the caps during normal engine maintenance. Idle mixture should be adjusted only in the case of major carburetor overhaul, throttle body replacement or high idle CO level as determined by inspection.
Idle Speed and Mixture – Holley 2300
All adjustments are same as previously described except as follows: On models equipped with idle stop solenoid, adjust idle stop solenoid screw to give 1000 rpm, then adjust idle mixture adjusting screw to specified rpm. Turn idle mixture screw in (leaner mixture) until engine speed drops 20 rpm, then turn out 1/4 turn. Disconnect lead at idle stop solenoid (throttle level will rest against regular stopscrew.) Adjust this stopscrew for idle speed of 500 rpm. Do not change setting of idle stop solenoid stopscrew or idle mixture screw
Fast Idle (1977-1979)
Use choke valve measuring gage J-26701. Rotate degree scale of tool until zero is opposite pointer. With choke completely closed place magnet squarely on top of choke valve. Rotate bubble until it is centered. Rotate scale so that number of degrees specified in opposite pointer. Place cam follower on second step of cam next to high step. Close choke by pushing upward on choke coil lever. To adjust, bend tang on fast idle cam until bubble is centered. Remove gage.
With slow idle speed correctly adjusted, fully open choke and make sure fast idle cam follower is off steps of cam. With dashpot fully compressed, adjust for 1/16″ clearance between dashpot plunger and throttle lever.
Remove the air cleaner and check to see that choke valve and rod more freely. Disconnect choke rod at choke lever. Check choke adjustment by holding choke valve closed and position rod so that it contacts stop. If necessary, adjust rod length by bending rod at offset. Bend must be such that rod enters choke lever hole freely and squarely. Connect rod at choke lever and install air cleaner.
Air Injection Reactor (A.I.R.) – Description and Operation
The A.I.R. system is used to burn the unburned portion of the exhaust gases to reduce its hydrocarbon and carbon monoxide content. The system forces compressed air into the exhaust manifold where it mixes with the hot exhaust gases. The hot exhaust gases contain unburned particles that complete their combustion when the addition air is supplied.
The system consists of: An air pump, diverter valve, check valve(s), AIR pipe assemblies and connecting hoses and fittings.
Carburetors and distributors for AIR engines are made to be used with the system and should not be replaced with components intended for use with engines that do not have the system.
The air pump is a two-vane pump which compresses fresh filtered air and injects it into the exhaust manifold. The pump consists of: a housing, centrifugal filter, set of vanes that rotate about the centerline of pump housing bore, the rotor, and the seals for the vanes. The centrifugal filter is replaced by first removing the drive belt and pump pulley; then pulling filter off with pliers. Care should be taken to prevent fragments from entering the air intake hole. NOTE: A new filter may squeal when first put into operation. Additionally, GREAT CARE should be taken in working on the compressor as the aluminum used is quite soft and thin.
The air pump is operating satisfactorily when the air flow from it increases as engine speed increases. The air hoses should be replaced only with hoses which are designed for AIR system use, as no other type hoses can withstand the high temperature.
Check and Adjust Dwell
Start engine then check ignition dwell. With engine running at idle, raise the adjustment screw window and insert an Allen wrench in the socket of the adjusting screw. Turn the adjusting screw as required until a dwell reading of thirty degrees is obtained. A two degree variation is allowable for wear. Close access cover fully to prevent the entry of dirt into the distributor. If a dwell meter is not available, turn adjusting screw clockwise until engine starts to misfire, then turn screw one-half turn in the opposite direction to complete adjustment.
Slowly accelerate engine to 1500 rpm and note dwell reading. Return engine to idle and note dwell reading. If dwell variation exceeds specifications, check for worn distributor shaft, worn distributor shaft bushing or loose breaker plate.
Remove distributor cap, clean cap and inspect for cracks, carbon tracks and burned or corroded terminals. Replace cap where necessary. Clean rotor and inspect for damage or deterioration. Replace rotor where necessary. Replace brittle, oil soaked or damaged spark plug wires. Install all wires to proper spark plug. Proper positioning of spark plug wires in supports is important to prevent cross-firing. Tighten all ignition system connections. Replace or repair any wires that are frayed, loose or damaged.
Disconnect the distributor spark advance hose and plug the vacuum source opening. Start engine and run at idle speed. Aim timing light at timing tab. The markings on the tabs are in two degree increments (the greatest number of markings on the “A” side of the “Q”). The “O” marking is TDC (Top Dead Center) and the BTDC settings fall on the “A” (advance) side of the “O”. Adjust the timing by loosening the distributor clamp and rotating the distributor body as required, then tighten the clamp, and recheck timing. Stop engine and remove timing light and reconnect the spark advance hose.
Inspect each plug individually for badly worn electrodes, glazed, broken or blistered porcelains and replace plugs where necessary. Clean serviceable spark plugs thoroughly, using an abrasive-type cleaner such as sand blast. File the center electrode flat. Inspect each spark plug for make and heat range. All plugs must be of the same make and number. Adjust spark plug gaps to .035 in. using a round feeler gauge. If available, test plugs with a spark plug tester. Inspect spark plug hole threads and clean before installing plugs. Install spark plugs with new gaskets and torque to specifications. Connect spark plug wiring.
Transistorized Distributor (H.E.I. System)
There are no moving parts in the ignition pulse amplifier, and the distributor shaft and bushings have permanent type lubrication, therefore no periodic maintenance is required for the magnetic pulse ignition system.
Distributor (Breaker Point System)
Check the distributor centrifugal advance mechanisms by turning the distributor rotor in a clockwise direction as far as possible, then releasing the rotor to see if the springs return it to its retarded position. If the rotor does not return readily, the distributor must be disassembled and the cause of the trouble corrected.
Check to see that the vacuum spark control operates freely by turning the movable breaker plate counter-clockwise to see if the spring returns to its retarded position. Any stiffness in the operation of the spark control will affect the ignition timing. Correct any interference or binding condition noted.
Examine distributor points and clean or replace if necessary. Contact points with an overall gray color and only slight roughness or pitting need not be replaced. Dirty points should be cleaned with a clean point file. Use only a few strokes of a clean, fine-cut contact file. The file should not be used on other metals and should not be allowed to become greasy or dirty. Never use emery cloth or sandpaper to clean contact points since particles will embed and cause arcing and rapid burning of points. Do not attempt to remove all roughness nor dress the point surfaces down smooth. Merely remove scale or dirt. Clean cam lobe with cleaning solvent, and rotate cam lubricator wick end (or one-hundred-eighty degrees as applicable). Replace points that are burned or badly pitted.
Where prematurely burned or badly pitted points are encountered, the ignition system and engine should be checked to determine the cause of trouble so that it can be eliminated. Unless the condition causing point burning or pitting is corrected, new points will provide no better service than the old points.
Check point alignment then adjust distributor contact point gap to .019″ (new points) or .016″ (used points). Breaker arm rubbing block must be on high point of lobe during adjustment. If contact points have been in service, they should be cleaned with a point file before adjusting with a feeler gauge.
Check distributor point spring tension (contact point pressure) with a spring gauge hooked to breaker lever at the contact and pull exerted at 90 degrees to the breaker lever. The points should be closed (cam follower between lobes) and the reading taken just as the points separate. Spring tension should be 19-23 ounces. If not within limits, replace. Excessive point pressure will cause excessive wear on the points, cam and rubber block. Weak point pressure permits bouncing or chattering, resulting in arcing and burning of the points and an ignition miss at high speed.
Install rotor and distributor cap. Press all wires firmly into cap towers.
Battery and Battery Cables
The top of the battery should be clean and the battery hold-down properly tightened. Particular care should be taken to see that the top of the battery is kept clean of acid film and dirt. When cleaning batteries, wash first with a dilute ammonia based or soda solution to neutralize any acid present and then flush off with clean water. Keep vent plugs tight so that the neutralizing solution does not enter the cell. The hold-down bolts should be kept tight enough to prevent the batter from shaking around in its holder, but they should onto be tightened to the point where the battery case will be placed under a severe strain.
To ensure good contact, the battery cables should be tight on the battery posts. Oil battery terminal felt washer. If the battery posts or cable terminals are corroded, the cables should be cleaned separately with a soda solution and wire brush. After cleaning and before installing clamps, apply a thin coating of a petrolatum to the posts and cable clamps to help slow corrosion.
If the battery has remain undercharged, check for loose or defective fan belt, defective alternator, high resistance in the charging circuit, oxidized regulator contact points, or a low voltage setting. If the battery has been using too much water, the voltage output is too high.
Inspect for deteriorated or plugged hoses. Inspect all hose connections. On engines with closed element air cleaners, inspect crankcase ventilation filter and replace if necessary. On engines with open element air cleaners, remove flame arrestor and wash in solvent then dry with compressed air.
Check the brake fluid regularly, for as the brake pads wear the level will drop rapidly. It should be replenished only with the recommended fluid. Check disc brake assemblies to see if they are wet; it would indicate a leaking cylinder.
Disc brakes do not need periodic adjustments; they are self adjusting. The pads should be replaced when the friction material gets down to 1/16″. This is when the groove in the center of the pad is gone. Check by removing wheel and looking directly into caliper.
Parking Brake (1977-1979)
Raise the vehicle and remove the rear wheels. Loosen the equalizer check nuts until the levers move freely to the “off” position with slack in the cables. Turn the disc until the adjusting screw is visible through the hole in the disc. Insert a screwdriver and tighten the adjusting screw by moving the screwdriver handle upward. Adjust both sides. Tighten until the disc will not move, then back off six to eight notches. Install the wheels and place the brake handle in the applied position – 13 notches. Tighten the check nuts until an 80 pound pull is required to pull the handle into the fourteenth notch. Torque the check nuts to70in. lbs. With the hand brake off, there should be no dragon either of the rear wheels.
Clutch Pedal Play
Check clutch action by holding pedal 1/2″ from floor and move shift lever between first and reverse several times, with engine running. If shift is not smooth adjust clutch. Free play with pedal released is approx. 1-1/4″ to 2″ and 2″ to 2-1/2″ for heavy duty.
At clutch lever near firewall remove clutch return spring. To decrease clutch pedal free play remove clutch pedal return spring and loosen lower nut on clutch pedal rod; take up play with upper nut. Continue until proper play is obtained, then securely tighten top nut and replace spring. To increase pedal play work nuts in opposite sequence.
Clutch Adjustment (1975-1982)
Disconnect the clutch return spring at the cross shaft. Push the clutch lever until the pedal is against the rubber stop under the dash. Loosen the two shaft locknuts and push the shaft until the throwout bearing just touches the pressure plate spring. Tighten the top locknut toward the swivel until the distance between it and the swivel is 0.4″. Tighten the bottom locknut against the swivel. The pedal free travel should not be 1-1/2″.
Disconnect control linkage at carburetor throttle lever. Hold carburetor throttle lever in wide position. Pull control linkage to wide open position. (On vehicles equipped with automatic transmission, pull through detent.) Adjust control linkage to freely enter hole in carburetor throttle lever. Connect control linkage at throttle lever.
Throttle Linkage Adjustment (Powerglide)
Remove air cleaner, disconnect accelerator linkage at carburetor. Disconnect accelerator return and trans. road return springs. Pull upper rod forward until transmission is through detent. Open carburetor wide open, at which point ball stud must contact end of slot in upper rod. Adjust swivel on end of rod if necessary.
Pull detent switch driver to rear until hole in switch body lines up with hole in driver. Insert a 3/16″ pin through hole to depth of 1/8″, and loosen mounting bolts. Open throttle fully and move switch forward until lever touches accelerator lever. Tighten mounting bolt and remove pin.
EGR Valve Check
A rough idling engine may be caused by a malfunction of the valve. Check by pinching vacuum hose to carburetor with engine idling. If idling smooths out, the valve should be removed for cleaning or replacement if something appears to be broken.
Lubrication – Engine Oil
The car should be standing on level ground and the oil level checked with the dipstick. Withdraw the dipstick, wipe it with a clean rag, replace and withdraw again. The mark made by the oil on the lower end of the dipstick will indicate the oil level. If necessary, oil should be added through the filler cap. Never let the oil level fall so low that it does not show at all on the dipstick. If in doubt, it is better to have a bit too much oil than too little. Never mix oils of different brands, the additives may not be compatible.
Engine Oil Drain and Replacement
Place a pan under the oil pan drain plug and remove plug. Be sure pan is of a large enough capacity to hold the oil. Move pan under filter and remove filter by turning if counterclockwise. Clean gasket surface of cylinder block. Coat gasket of new filter with engine oil. Thread filter into adapter. Tighten securely by hand. Do not overtighten filter. Remove drop pan.
Remove drain pan. Inspect oil pan drain plug gasket and replace if broken, cracked, or distorted. Install drain plug and tighten. Fill crankcase to required level with recommended oil. Operate engine at fast idle and check for oil leakage.
When changing oil filter, add one additional quart.
Check fluid level with engine idling, transmission in neutral and engine at normal operating temperature. Add fluid as needed to bring level to mark. Do not overfill.
Every 12,000 miles or sooner, depending on service, remove fluid from sump and add new fluid. Operate transmission and check fluid level. Every 24,000 miles the transmission sump strainer of the Turbo Hydra-Matic transmission should be replaced.
Refill Capacity: Powerglide – 2 quarts, Turbo Hydra-Matic – 7-1/2 quarts.
Raise car on lift, clean dirt and grease from area around the filler plug. Plug is located on side of transmission case. Remove plug and place finger tip inside hole. The oil should be just about level with the bottom edge of the hole. Add oil as needed, using a plastic syringe.
Change cam lubricator end for end at 12,000 mile intervals. Replace at 24,000 mile intervals.
With the car standing level, clean dirt and grease from area around filler plug. Remove plug and place finger tip inside hole. The oil should be just about level with the bottom edge of the hole. Add oil, with a plastic syringe, as needed.
1978 Corvette Dealers Sales Brochure
Download this 1978 Corvette Dealers Sales Brochure for a quick look at the features of the car.