Chevrolet K5 Blazer

Chevrolet K5 Blazer

Manufacturer	General Motors
Production	1969–1994
Assembly	Janesville, Wisconsin
Successor	Chevrolet Tahoe GMC Yukon
Class	Full-size SUV
Body style(s)	2-door SUV
Layout	Front engine, rear-wheel drive / four-wheel drive

The K5 Blazer was the smallest full size SUV version of the General Motors C/K Trucks family. Introduced to the Chevrolet line in 1969, the full-size Blazer was replaced in 1995 by the Chevrolet Tahoe. In 1970, GMC introduced its own model of the truck, called the Jimmy, which lasted until the 1992 GMC Yukon. Both were based on the short wheelbase trucks and were available with either rear-wheel drive or four-wheel drive. Its long wheelbase relative (with an integrated rear body) is known as the Chevrolet Suburban.

The K5 Blazer and Jimmy had removable tops for the first few years until 1976 when a half-cab body style was introduced. Smaller models, the S-10 Blazer and S-15 Jimmy, were introduced alongside these trucks in 1983. The original Blazer and Jimmy remained in production until 1991; 1992 saw the introduction of a new K1500 Blazer (and the rebadged GMC Yukon) on the GMT400 platform. After 1994, the Blazer was renamed the Chevrolet Tahoe.

1969-1972

First generation

Also called	GMC K5 Jimmy
Production	1969–1972
Body style(s)	2-door SUV
Engine(s)	250 in³ Straight-6 292 in³ Straight-6 307 in³ Small-block V8 350 in³ Small-block V8
Transmission(s)	3-speed automatic 4-speed manual

The original K5 was a short wheelbase truck. It was available in 1969 as 4-wheel drive only; in 1970, a two-wheel-drive model was offered. There were four choices for power plants: the 250 in straight-6, the 292 straight-6, the 307 V8, and the 350 V8.

The Blazer was designed and marketed to compete with International Harvester Scout and the Ford Bronco. Both of these were originally aimed at the short Jeep CJ series, which were much smaller than other trucks. The great innovation of the Blazer was to simply offer a shortened pickup truck, which both increased interior space, and lowered the cost of production with a shared platform. The Blazer quickly became popular. For the first time, it married the off-road capabilities of the Scout with the "luxury" features like air conditioning and automatic transmissions routinely available on pickup trucks. By 1970, the Blazer was already outselling both of its older rivals. Ford, Dodge, and even Jeep would counter with similar shortened pickups, with the Ford Bronco, Dodge Ramcharger and Jeep Cherokee.

The two-wheel drive version had independent front suspension, and rear trailing arms, both with coil springs. The four-wheel drive version had a solid front axle and used leaf springs front and rear. Both versions used drum brakes front and rear until 1971, when the entire GM light truck line got standard front disks, while retaining drums in the rear.

There was also a choice between a three-speed automatic transmission Turbo Hydromatic (TH350), a three-speed manual transmission, and a four-speed Saginaw Muncie (SM465) manual transmission. Two transfer cases were offered: the Dana 20, available only with the manual transmission, or the NP-205, available with either transmission.

Engines:

4.1 L (250 in³) 250 I6 (1969-1984)
4.8 L (292 in³) 292 I6 (1970-1971)
5.0 L (307 in³) 307 V8 (1969-1973)
5.7 L (350 in³) 350 V8 (1969-1991)

Transfer cases:

Dana 20 - gear driven part-time four-wheel drive
NP-205 - gear driven part-time four-wheel drive

1973-1991

Second generation

Also called	GMC K5 Jimmy
Production	1973-1980 2nd generation 1981–1991 3rd geration slightly different Hood and Fenders
Engine(s)	250 in³ straight six 292 in³ straight six 305 in³ Small-block V8 307 in³ Small-block V8 350 in³ Small-block V8 400 in³ Small-block V8 6.2 L Detroit Diesel V8
Transmission(s)	4-speed SM465 manual 3-speed TH350 automatic 3-speed TH400 automatic 4-speed 700-R4 automatic
Wheelbase	106.5 in (2705 mm)
Length	184.8 in (4694 mm)
Width	79.6 in (2022 mm)
Height	73.8 in (1875 mm)
Fuel capacity	31 US gallons (117.3 L/25.8 imp gal)

Third generation Chevrolet K5 Blazer with a grille style that suggests its for the years of 1981-1982

1987 Chevrolet K5 Blazer

In 1973, GM's line of full-size trucks was redesigned and updated. Although rear-wheel drive Blazers were manufactured until 1982, the majority sold were four-wheel drive.

Until 1976, the K5 had a removable convertible top. After this, a half-cab design was used until 1991.

Although the GMT400 platform was introduced in the spring of 1987 as a 1988 model, the K5 Blazer, Suburban, and crew-cab trucks retained the earlier platform until 1991. In 1989, the front grille was changed to resemble the squared-off ones used on the GMT400 series of pickups.

The K5 Blazer is very popular in the off-roading scene. It is a strong truck with the 350 V8 (which was the optional powerplant), the gear driven NP-205 and ten and twelve bolt axles. It is very easy to upgrade this engine, because there are many companies with performance parts available. Later models produced after 1980 used the chain-driven NP208 transfer case, and the NP241 after 1988.

Since 1981 (in the wake of the 1973 Arab Oil Embargo and the 1979 energy crisis), Chevrolet and GMC used the smaller displacement 305s with a 9.2:1 compression ratio. These engines produced nearly as much torque as the 350, giving a similar driving feel. However, these powerplants were underpowered and susceptible to detonation (engine knocking), especially with the electronic spark control module. To achieve the 9.2:1 compression ratio, the cylinder head chambers were smaller, measuring 54 cc instead of 60 cc. Despite a camshaft swap, some Blazer owners swapped out the 305s in favor of 350s, since the smaller displacement powerplant was used in all Chevrolet/GMC pickups and passenger cars.

1982 saw the Detroit Diesel 6.2 introduced; diesel-powered K5s are sought after (especially for diesel conversions running biodiesel and/or straight vegetable oil).

After 1987, when throttle-body fuel injection was introduced in the truck powerplants, the 350 was made the standard powerplant.

There are also a variety of suspension and body lifts available for the K5 Blazer. It is easy to clear 33 inch (838 mm) tires stock or with a two inch (51 mm) lift or 35 inch (889 mm) tires with a four or six inch (102 or 152 mm) lift.

Engines:

4.1 L (250 in³) 250 I6 (1973-1984)
4.3 L (262 in³) 262 I6 (1985-1986)
5.0 L (305 in³) 305 V8 (1976-1987)
5.0 L (307 in³) 307 V8 (1973)
5.7 L (350 in³) 350 V8 (1973-1991)
6.6 L (400 in³) 400 V8 (1975-1980)
6.2 L (379 in³) Detroit Diesel V8 (1982-1991)

Transmissions:

Turbo Hydromatic TH350 three-speed automatic (1973-1981)
Turbo Hydromatic TH400 three-speed automatic (1974-1979)
700R4 (4L60) four-speed overdrive automatic (1982-1991)
Saginaw SM465 four-speed manual (1973-1991)

Transfer cases:

Dana 20 - gear driven part-time four wheel drive (1973)
NP-205 - gear driven part-time four wheel drive (1973-1980)
NP-203 - chain driven full-time four wheel drive (1973-1979)
NP-208 - chain driven part-time four wheel drive (1981-1988)
NP-241 - chain driven part-time four wheel drive (1988-1991)

Axles:

Dana 44 - Front axle (1973-1977/78)
GM Corporate 10 Bolt - Front axle (1977/78-1991)
GM Corporate 12 Bolt - Rear axle (1973-1981)
GM Corporate 10 Bolt - Rear axle (1982-1991)

1992-1994

Fourth generation

Also called	GMC Yukon
Production	1992–1994
Engine(s)	5.7 L V8
Transmission(s)	4-speed automatic 5-speed manual
Wheelbase	111.5 in (2832 mm)
Length	187.7 in (4768 mm)
Width	76.4 in (1941 mm)
Height	71 in (1803 mm)
Fuel capacity	30 US gallons (113.6 L/25.0 imp gal)

The full-size Blazer was updated in 1992 on the new GMT400 platform and lasted through the 1994 model year in name only. In 1995 the fullsize Blazer was rebadged as the Tahoe up until 1999, which was the last model year for this 2-door SUV. A matching 2-door GMC Yukon on the GMT400 platform was produced from 1992 to 1997. These also saw the 6.5 liter Detroit Diesel V8's.

Miscellaneous

Around 1981, a prototype K5 Blazer was used as a testbed for a military CUCV vehicle. Between 1983 and 1986, what is known as the M1009 CUCV was the production militarized version of the civilian K5. The only differences are the lack of an air conditioner and an additional leaf spring in the suspension. A majority of them are painted olive drab green (or in the black-brown-green camouflage pattern used by NATO forces if an M1009 was stationed in Western Europe) until its use in Operation Desert Storm where M1009s were painted desert tan. All M1009s, including its derivatives, are powered with the 6.2 L Diesel powerplant.

The M1009s have a split 24/12 volt electrical system. Most of the truck actually runs on 12 volts. It has two separate 12v alternators and batteries wired in series, only the glow plug system, the starter, and the jumper cable jack are wired to the 24 volt terminals. everything else in the truck runs on 12 volts. The glow plugs are actually 12 volt glow plugs, with a resistor pack on the firewall to drop the 24v down to 12v. This resistor pack can be bypassed and the glow plugs run directly off of the 12v battery. If this is done and the 24v starter is replaced with a standard 12v starter the second alternator and battery are no longer needed. (If this is done then the military 24v jump start plug in the grille will need to be disconnected as well.)

Some decommissioned M1009s end up in law enforcement use (e.g. with the Los Angeles County Sheriff's Department) or sold through government auctions. Many of these Blazers are obsolete as military vehicles in favor of the Humvee.

Appearances in Popular Media

A modified silver and red K5 Blazer with the "Cheyenne Package" and a custom targa hardtop was prominently featured in the 1974 disaster film Earthquake.

A demilitarized K5 Blazer is shown in use by the local law enforcement in episode 2, season 3 of Stargate: SG1 "Seth"