Powerglide
Encyclopedia
The Powerglide is a two-speed automatic transmission
designed by General Motors
. It was available primarily on Chevrolet
from January, 1950 through 1973, although some Pontiac
models also used this automatic transmission, extensively on models produced for the Canadian
market with Chevrolet powertrains. When introduced on upper-level Chevrolet models in 1950, the Powerglide represented the first automatic transmission offered in a low-priced automobile; in contrast, Ford
did not offer their automatic transmission until 1951, while Plymouth car buyers had to wait until 1954. The transmission was simple and very durable, which satisfied customers.
In 1962, GM started building Powerglides in aluminum, primarily for use in the new model Chevy II, which required a lightweight transmission for its compact body, and discontinued the cast iron Powerglides in 1963. A heavy duty version of Aluminum Powerglide was offered for passenger cars equipped with the 409 cubic inch V8 engine
, and Chevrolet light trucks using a 1.76:1 reduction planetary gear set, instead of the usual 1.82:1. With a 3.31 axle, Car and Driver magazine noted a full-throttle up shift speed of 76 mph (122.3 km/h) to direct with the 409-4bbl 340 hp engine in a contemporary road test. Most of the V8/Powerglide transmissions came with the 1.76 gear set. One notable exception was the export version of the transmission, which used only the 1.82 ratio and was used by Holden
in Australia behind their Australian built 6-cylinder
and V8 engines. Holden vehicles fitted with Chevrolet V8 engines used the 1.76 ratio gear-set.
The Powerglide continued to serve as Chevrolet's main automatic transmission through the 1960s, when a new three-speed automatic transmission called Turbo-Hydramatic 400
(1965 introduction) began to be phased in. They were introduced in Buicks and Cadillacs the previous year.
Usually, Powerglides were coupled behind the small block V8s
and the third-generation inline six cylinder engine and inline four-cylinder engines. By the late 1960s, demand for two-speed automatic transmissions was dwindling as buyers were demanding three-speed units (Ford, Chrysler and American Motors
had already switched entirely to three-speed automatics by this time). In 1969, the three-speed Turbo Hydramatic 350 (THM350) was introduced as a light-duty companion to the Turbo-hydramatic 400, and made available on virtually all Chevrolet cars and trucks with six-cylinder or small and medium sized V8 engines, as well as intermediate sized cars of other GM divisions.
The Powerglide lingered on as a low-cost automatic transmission option primarily for six-cylinder Chevrolet Nova
and four-cylinder Chevrolet Vega
until it was phased out after the 1973 model year. They were also used in the DJ-5 'Dispatcher' jeeps sold for light commercial use, and best known for their service with the US Postal Service.
case and is known as the "Cast Iron Powerglide". The "Cast Iron Powerglide" was used until 1963, when it was revamped as "Aluminum Powerglide" where its case and several of its other parts were made of aluminum. The Aluminum Powerglide was used from 1962 until it was replaced with the Turbo-hydramatic series of transmission in 1973. The Aluminum Powerglide is still used today as a racing transmission of choice by many racers mainly for the fact that it only shifts once, and for its extreme durability. It is also possible to purchase all the parts needed to build an Aluminum Powerglide from scratch from most racing parts vendors.
Prior to 1967, transmission ID numbers contained the plant prefix code, month and date of production (expressed numerically) and a shift code (D = Day, N = Night). From 1967 on, the ID number contained the transmission type or plant prefix, Date (coded below) and a shift code. The constants in decoding the trans ID number are the date the transmission was produced.
The transmission identification number or source serial number (chassis vin) is usually located close to the transmission code. This number will contain a division identification number, the model year, and the assembly plant and production sequence (last 6 digits) of the vehicle identification number
(VIN) stamped onto the transmission.
, a triple turbine continuously variable automatic transmission
with concurrent ratios whose design was similar to that of Buick's Flight Pitch Dynaflow, subsequently called Triple Turbine (full technical description). The Turboglide
, only offered with V8 engines, was more expensive (by about $50) than the Powerglide and did not have wide acceptance, in part due to failures in 1957-58 models, which were addressed by a significantly upgraded version for 1959.
, using the basic design principles of Powerglide was optional in the rear-engined, air-cooled, horizontally-opposed six-cylinder Corvair
compact, available for all years of its production (1960–69).
due to its strength and simplicity. Powerglides are also popular in mud racing
and monster truck
racing. In the first few years after introduction, they became known as the "Slip-N-Slide Powerglide",due to the fluid coupling, as opposed to the mechanical coupling of a clutch-driven gearbox), and the "Positive-Pop transmission" This last is due to the characteristic "bump" or "pop" which occurs as the transmission is put into gear from neutral.
Currently Robert Campisi from Australia holds the World Record for the fastest run using a Powerglide transmission, clocking 5.95s at 260mph in his Twin Turbo Ford Mustang in September 2011.
Automatic transmission
An automatic transmission is one type of motor vehicle transmission that can automatically change gear ratios as the vehicle moves, freeing the driver from having to shift gears manually...
designed by General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
. It was available primarily on Chevrolet
Chevrolet
Chevrolet , also known as Chevy , is a brand of vehicle produced by General Motors Company . Founded by Louis Chevrolet and ousted GM founder William C. Durant on November 3, 1911, General Motors acquired Chevrolet in 1918...
from January, 1950 through 1973, although some Pontiac
Pontiac
Pontiac was an automobile brand that was established in 1926 as a companion make for General Motors' Oakland. Quickly overtaking its parent in popularity, it supplanted the Oakland brand entirely by 1933 and, for most of its life, became a companion make for Chevrolet. Pontiac was sold in the...
models also used this automatic transmission, extensively on models produced for the Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
market with Chevrolet powertrains. When introduced on upper-level Chevrolet models in 1950, the Powerglide represented the first automatic transmission offered in a low-priced automobile; in contrast, Ford
Ford Motor Company
Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...
did not offer their automatic transmission until 1951, while Plymouth car buyers had to wait until 1954. The transmission was simple and very durable, which satisfied customers.
History
The 1950, 1951, and 1952 Powerglide transmissions did not automatically shift between low and high (direct drive) which made for very sluggish take-offs and many drivers started in "Low" and shifted to "Drive" at about 30–40 mph (48.3–64.4 km/h), which was hard on the transmission. The 1953 and later units when in "Drive" started in low and automatically up shifted to high at a speed determined by the throttle opening. By the mid-1950s, more than half of all new Chevrolets were sold with Powerglide.In 1962, GM started building Powerglides in aluminum, primarily for use in the new model Chevy II, which required a lightweight transmission for its compact body, and discontinued the cast iron Powerglides in 1963. A heavy duty version of Aluminum Powerglide was offered for passenger cars equipped with the 409 cubic inch V8 engine
Chevrolet Big-Block engine
The Chevrolet big block is a series of large displacement V8 engines that were developed in the USA during the 1950s and 1960s. As American automobiles grew in size and weight following the Second World War the engines powering them had to keep pace...
, and Chevrolet light trucks using a 1.76:1 reduction planetary gear set, instead of the usual 1.82:1. With a 3.31 axle, Car and Driver magazine noted a full-throttle up shift speed of 76 mph (122.3 km/h) to direct with the 409-4bbl 340 hp engine in a contemporary road test. Most of the V8/Powerglide transmissions came with the 1.76 gear set. One notable exception was the export version of the transmission, which used only the 1.82 ratio and was used by Holden
Holden
GM Holden Ltd is an automaker that operates in Australia, based in Port Melbourne, Victoria. The company was founded in 1856 as a saddlery manufacturer. In 1908 it moved into the automotive field, before becoming a subsidiary of the U.S.-based General Motors in 1931...
in Australia behind their Australian built 6-cylinder
Holden motor
The Holden straight-six motor is a straight-six engine produced by General Motors–Holden's in Australia between 1948 and 1986. Initially dubbed the Grey motor alluding to the colour of the cylinder block, later iterations came in the form of a Red, Blue, Black and the four-cylinder Starfire engine...
and V8 engines. Holden vehicles fitted with Chevrolet V8 engines used the 1.76 ratio gear-set.
The Powerglide continued to serve as Chevrolet's main automatic transmission through the 1960s, when a new three-speed automatic transmission called Turbo-Hydramatic 400
Turbo-Hydramatic
Turbo-Hydramatic is the registered tradename of a family of automatic transmissions developed and produced by General Motors. These transmissions mate a three-element torque converter to a Simpson planetary geartrain, providing three forward speeds plus reverse.The Turbo-Hydramatic series was...
(1965 introduction) began to be phased in. They were introduced in Buicks and Cadillacs the previous year.
Usually, Powerglides were coupled behind the small block V8s
Chevrolet Small-Block engine
The Chevrolet small-block engine is a series of automobile V8 engines built by the Chevrolet Division of General Motors using the same basic small engine block...
and the third-generation inline six cylinder engine and inline four-cylinder engines. By the late 1960s, demand for two-speed automatic transmissions was dwindling as buyers were demanding three-speed units (Ford, Chrysler and American Motors
American Motors
American Motors Corporation was an American automobile company formed by the 1954 merger of Nash-Kelvinator Corporation and Hudson Motor Car Company. At the time, it was the largest corporate merger in U.S. history.George W...
had already switched entirely to three-speed automatics by this time). In 1969, the three-speed Turbo Hydramatic 350 (THM350) was introduced as a light-duty companion to the Turbo-hydramatic 400, and made available on virtually all Chevrolet cars and trucks with six-cylinder or small and medium sized V8 engines, as well as intermediate sized cars of other GM divisions.
The Powerglide lingered on as a low-cost automatic transmission option primarily for six-cylinder Chevrolet Nova
Chevrolet Nova
The Chevrolet Chevy II/Nova is a compact automobile manufactured by the Chevrolet division of General Motors produced in four generations for the 1962 through 1979 model years. Nova was the top model in the Chevy II lineup through 1968. The Chevy II nameplate was dropped, Nova becoming the...
and four-cylinder Chevrolet Vega
Chevrolet Vega
The Chevrolet Vega is a subcompact, two-door automobile that was produced by the Chevrolet division of General Motors for the 1971-1977 model years. Named after the star Vega, the car was powered by a lightweight aluminum-block inline four-cylinder engine...
until it was phased out after the 1973 model year. They were also used in the DJ-5 'Dispatcher' jeeps sold for light commercial use, and best known for their service with the US Postal Service.
Types
There were two primary types or versions of the Powerglide. The Powerglide transmission introduced in 1950 had a cast ironCast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
case and is known as the "Cast Iron Powerglide". The "Cast Iron Powerglide" was used until 1963, when it was revamped as "Aluminum Powerglide" where its case and several of its other parts were made of aluminum. The Aluminum Powerglide was used from 1962 until it was replaced with the Turbo-hydramatic series of transmission in 1973. The Aluminum Powerglide is still used today as a racing transmission of choice by many racers mainly for the fact that it only shifts once, and for its extreme durability. It is also possible to purchase all the parts needed to build an Aluminum Powerglide from scratch from most racing parts vendors.
Identification
General Motors transmission have markings to identify;- - Casting numbers on the case and extension housing.
- - Date Casting Codes
- - Assembly Date Code Stamping - can be stamped anywhere...
- - Chassis Vin Number stamping or "source serial number"- beginning in 1962
Prior to 1967, transmission ID numbers contained the plant prefix code, month and date of production (expressed numerically) and a shift code (D = Day, N = Night). From 1967 on, the ID number contained the transmission type or plant prefix, Date (coded below) and a shift code. The constants in decoding the trans ID number are the date the transmission was produced.
- Pre-67 Example: C213N - (C = Cleveland Powerglide, February 13, Night Shift)
- Post-67 Example: P9E03 - (P = TYPE, 9 = year (1969), E = Month, 03 = Day of Month)
The transmission identification number or source serial number (chassis vin) is usually located close to the transmission code. This number will contain a division identification number, the model year, and the assembly plant and production sequence (last 6 digits) of the vehicle identification number
Vehicle identification number
A Vehicle Identification Number, commonly abbreviated to VIN, is a unique serial number used by the automotive industry to identify individual motor vehicles. VINs were first used in 1954...
(VIN) stamped onto the transmission.
- Example: 19N500001
Safety issues
The Powerglide used a P-N-D-L-R selector sequence through 1957, changed in 1958 to the now-standard P-R-N-D-L sequence. The earlier sequence had been criticized on safety grounds for placing reverse after a forward gear, instead of having neutral between reverse and the forward ranges. For example, a driver could easily overshoot L and go into R, possibly causing permanent damage and/or catastrophic failure.Turboglide
From 1957-1961, Chevrolet also produced the TurboglideTurboglide
The Turboglide is a Chevrolet constant torque automatic transmission that made its debut as an optional transmission on Chevrolet V8 passenger cars for 1957. It consisted of a concurrently geared planetary gearbox with a 'switch pitch' dual pitch torque converter stator...
, a triple turbine continuously variable automatic transmission
Continuously variable transmission
A continuously variable transmission is a transmission that can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios...
with concurrent ratios whose design was similar to that of Buick's Flight Pitch Dynaflow, subsequently called Triple Turbine (full technical description). The Turboglide
Turboglide
The Turboglide is a Chevrolet constant torque automatic transmission that made its debut as an optional transmission on Chevrolet V8 passenger cars for 1957. It consisted of a concurrently geared planetary gearbox with a 'switch pitch' dual pitch torque converter stator...
, only offered with V8 engines, was more expensive (by about $50) than the Powerglide and did not have wide acceptance, in part due to failures in 1957-58 models, which were addressed by a significantly upgraded version for 1959.
Corvair Powerglide
Corvair PowerglideCorvair Powerglide
Chevrolet Corvair Powerglide is a two-speed automatic transmission designed specially for the then all-new 1960 Chevrolet Corvair compact car that emerged in the fall of 1959 as Chevrolet's competitor in the then booming small car market. The Corvair was powered by a six-cylinder rear engine that...
, using the basic design principles of Powerglide was optional in the rear-engined, air-cooled, horizontally-opposed six-cylinder Corvair
Chevrolet Corvair
-First generation :The 1960 Corvair 500 and 700 series four-door sedans were conceived as economy cars offering few amenities in order to keep the price competitive, with the 500 selling for under $2,000...
compact, available for all years of its production (1960–69).
Swapping
The Powerglide shares the same length, 27 spline output shaft, and transmission mounting as the THM 350; thus, the transmissions are easily interchangeable for owners wanting three speeds instead of two.Racing
Although it is a very old design, the Powerglide still has a strong following in drag racingDrag racing
Drag racing is a competition in which specially prepared automobiles or motorcycles compete two at a time to be the first to cross a set finish line, from a standing start, in a straight line, over a measured distance, most commonly a ¼-mile straight track....
due to its strength and simplicity. Powerglides are also popular in mud racing
Mud bogging
Mud bogging is a form of off-road motorsport popular in Canada and the United States in which the goal is to drive a vehicle through a pit of mud of a set length...
and monster truck
Monster truck
A monster truck is a pickup truck, typically styled after pickup trucks' bodies, modified or purposely built with extremely large wheels and suspension...
racing. In the first few years after introduction, they became known as the "Slip-N-Slide Powerglide",due to the fluid coupling, as opposed to the mechanical coupling of a clutch-driven gearbox), and the "Positive-Pop transmission" This last is due to the characteristic "bump" or "pop" which occurs as the transmission is put into gear from neutral.
Currently Robert Campisi from Australia holds the World Record for the fastest run using a Powerglide transmission, clocking 5.95s at 260mph in his Twin Turbo Ford Mustang in September 2011.