1951 Chevrolet 3100 1/2 ton pick up formerly BC Tel.

On Saturday June 28, 1947 Chevrolet released the Advance-Design 1947 series of trucks to replace the AK Series Pickup Truck. The Advance-Design Series was built until midway through 1955 when the 1955 Series II Task Force Series were introduced part way through the 1955 model year.

Interestingly this was General Motors’ first new postwar vehicles and the integrated headlights and horizontal grille made it instantly recognizable on the roads. The upgraded cab was fully welded, 8 inches wider and 7 inches longer than the previous trucks. The fresh air Windshield defrost and cab heater allowed three adults to sit in relative comfort on a fully adjustable seat.

During the war years most vehicle production was for the war effort and most were based on the 1942 design. But the engineers were hard at work planning for the generation of cars after the war was over. New trucks are usually designed after interviews with business owners as opposed to car owners. The biggest concern among business owners was larger cabs and better vision.

It has been written about that the reason the trucks go a design refresh before the others vehicles was that they had been in constant production since 1942 feeding the war effort and that the dies for making the bodies were probably in need of replacement.

Although the trucks had been upgraded throughout the model run, the following Task Force Series was a modern design replacing a virtually decades old truck. Interestingly, the 3100 1/2 ton cab was used through almost the entire line of trucks with new grilles and larger fenders, taller hoods. The one exception was the Cab Over design using a modified Cab.

The Advance-Design Series of trucks along with the similar GMC versions were the number one selling truck of the Era with 345,519 Chevrolet trucks built in 1949 with a base price of around $1200. The Chevrolet naming system was the 3100 (½-ton), 3600 (¾-ton), 3800 (1-ton), with Loadmaster and Thriftmaster being used on the larger sized trucks.

Production and assembly was done at 4 plants, Van Nuys California, Saint Louis, Missouri, Pontiac, Michigan and Janesville, Wisconsin.

This chassis was referred to as the “GM A platform” and was also used on the Chevrolet Suburban. The trucks were available as bare chassis for commercial truck body builders to outfit them for their customer’s needs. The spare tire and gas tanks were under the bed floor until 1949 when the gas tanks was moved into the cab behind the seat because it hampered certain custom body types.

From 1947–1953 power came from the venerable 216.5 cu. in. (3.5 L)   “Thrift-Master Six”  with a 3.50×3.75 bore and stroke and 6.5:1 compression. It utilized four main bearings, solid lifters, cast iron pistons, a single Carter Carb and used a combination of splash and pressure for lubrication. It produced 90 horsepower at 3,300 rpm and 174 lb.ft. of torque. For 1954 and 55 either the 235 cu in (3.9 L) or 261 cu in (4.3 L) was available.

The new truck featured two prominent gauges directly in the drivers line of site and an ashtray popped out from it’s hiding place among horizontal chrome bars. Directly to the right of the gauges were a vertical row of switches including controls for ignition switch, pull out throttle and a wiper switch. All trucks had a chromed speaker grille and if the optional  Delco AM radio was ordered it was installed above the radio grille and a speaker was installed.

The cab also had a large glovebox and the headliner was cardboard and standard equipment featured a dome light, adjustable instrument lighting, vacuum operated windshield wipers and black rubber floor mat. Items we take for granted were optional, such as hydraulic shock absorbers outside mirrors, heater/defroster, armrests and oil or fuel filters. Some were facotry options and some were installed by dealers.

Chevrolet marketed the Advance-Design Series of trucks as “the cab that breathes,” as it had a cowl-top vent along with passenger and driver vents. The seat was also more practical and comfortable and the bottom cushion easily lifted up to allow access to the floor mounted tool box. The seat slide slopped upward to the front so a shorter driver could adjust the seat closer to the pedals and higher for better visibility. The seat was upholstered in dark maroon leather-ette(Vinyl)

Much attention went into the bench seat design. The bottom cushion could easily be lifted up and out to give access to a toolbox under the floor. The seat it¬self, , could be adjusted for height and leg room by sliding it up and back on wedge-shaped floor runners. Moving the seat forward simultaneously angled it up¬ward, automatically adjusting it to the driver’s height so that a short person could see out just as easily as a tall one.

Forester green was the standard exterior colour, but a lighter green, maroon, beige, red, orange, black, white and two shades of blue. Optional chrome grille bars were available.

The 3100 and 3600 had fully synchromesh 3 speed transmissions while the 3800 had a four-speed with a granny low non synchro low gear. This tranny was optional on the 3600. The two lighter trucks used a 9.13″ clutch and 10.75″ clutch was standard on the 3800 and optional on the 3600 and 3800. Differential ratios were 4.11 on the 3600, 4.57 on the 3600 and 5.14 on the 3800. A “Hydramatic 4 speed being offered on the 1954 and 55 models.

According to the www.classic-car-history.com website: “Chevy’s 216-cid straight-six motor was retained, receiving only minor engine improvements. The carburetor accelerator pump was moved into the float bowl to keep the leather piston wet, and to help cold-engine driveability, the hand-choke activated a carb-mounted fast-idle cam. Older, ream-fit main bearings were replaced with the modern precision-type.”

The Advance-Design Series of trucks came on wheelbases 116 in (2,946 mm), 125.25 in (3,181 mm), 137 in (3,480 mm)

The 3100 pickup length for 1953-1955 was shortened 5″ from the 1947-1952’s 196.6 in (4,990 mm) to 191.3 in (4,860 mm)

The bodies for the trucks were stamped internally at Chevrolet and GMC while the car bodies were almost exclusively produced by Fisher bodies. Chevy and GMC also designed and built their own body dies and the stampings were pressed at GM’s Indianapolis, Indiana, facility and then shipped to assembly facilities.

 Differences according to www.wikipedia.org and www. auto.howstuffworks.com

1947 – Gasoline tank filler neck on passenger side of bed. No vent windows in doors. Hood side emblems read “Chevrolet” with “Thriftmaster” or “Loadmaster” underneath. Radios were first available in Chevrolet trucks as an “in dash” option on the “Advance-Design” body style.[5]

1948 – Manual transmission shifter now mounted on column instead of floor.

Early 1949 – Gasoline tank now mounted upright behind seat in cab; filler neck aft of passenger door handle.

Late 1949 – Hood side emblems no longer read “Thriftmaster” or “Loadmaster”, but are now numbers that designate cargo capacity: 3100 on ½ ton, 3600 on ¾ ton, 3800 on 1 ton.

1950 – Telescopic shock absorbers replace lever-action type. New rear quarter windows improved visibility Last year for driver’s side cowl vent, its handle is now flat steel, not maroon knob as in previous years. Trucks rode on 16-inch tubed-tires, with three body lengths available. A side-mount spare tire carrier between the cab and the left rear fender became optional.

The Korean Military conflict brought about a precious-metals shortage, with Automakers substituting chrome parts with plain steel. Most Chevy trucks came with a painted front grille.

1951 – Doors now have vent windows. Mid-year change from 9-board bed to 8 boards per bed. Last year for 80 MPH speedometer, chrome window handle knobs, and chrome wiper knob. the rear bumper and spare tire lock were deleted as a cost saving exercise. A windshield washer was now available along with hand held spotlight powered by the optional cigar lighter. The Korean war cause a shortage in chromium so all grilles were painted and with the scarcity of copper radiators became lighter and less heavy duty.

1952 – Outer door handles are now push button type as opposed to the previous turn down style. Speedometer now reads to 90 mph up from 80mph and dashboard trim is painted instead of chrome and changes to maroon window and wiper knobs. Mid-year, Chevrolet stops using the 3100-6400 designation on the hood.

1953 – Tinted glass was available along with a sidemount spare-tire carrier. Last year for the 216 in³ inline-six. Hood side emblems now only read 3100, 3600, 3800, 4400, or 6400 in large print. Door post ID plate now blue with silver letters (previous models used black with silver letters). Last year to use wooden blocks as bed supports. Factory-installed signals became optional in 1953.

1954 – Although an all-new truck was planned for the following year, 1954 Chevrolet trucks received a minor restyle, new front turn signals. a one-piece curved windshield, a new Grille changed from five horizontal slats to crossbar design commonly referred to as a “bull nose” grille. The dashboard was redesigned, featuring twin instrument dials, revised steering wheel and round tail lights round instead of rectangular. A new cargo box had a lower loading height, taller bed sides, and horizontal top rails. 3600 models gained a three-inch stretch in bed length. Chevrolet would use this style cargo box into the eighties. The Deluxe Comfortmaster Cab option gave the buyer corner windows, chrome window moldings, passenger-side sun visor, driver’s armrest, and dual horns.

The 216-cid “Stovebolt Six” motor, in use since the Thirties, was discontinued in favor of the 235-cid engine from Chevy’s Load-Master truck series. Improvements included stronger crankshaft and connecting rods, aluminum pistons, and full-pressure lubrication. With 7.5:1 compression ratio, horsepower was 112 at 3,700 rpm. Torque was 200 pound-feet at 2,000 rpm.

1955 First Series – Early 1955 Chevrolet trucks, referred to as the ‘1955 first series’ Similar to the 1954 model year, except redesigned hood-side emblems and modern open driveshaft in place of enclosed torque tube. The first-series trucks were built through March of 1955, replaced by Chevy’s ‘Task Force’ series. Also optional were electric windshield wipers, a foot-operated windshield washer, radio, heater, turn signals, and dash-mounted clock. A 3.9:1 axle ratio was used in 3100s for greater fuel economy.

Sources

www.en.wikipedia.org/wiki/Chevrolet_Advance_Design

www.classic-car-history.com/1947-1955-chevy-truck.htm

www.pickuptrucks.com/html/history/chev_segment5.html

www.conceptcarz.com/vehicle/z11566/Chevrolet-3100-GP.aspx

www.auto.howstuffworks.com/1954-chevrolet-series-3100-half-ton-pickups.htm

www.auto.howstuffworks.com/1947-1955-chevrolet-trucks.htm