Build A Powerglide Transmission For Your Drag Race Car

Posted by on Tuesday, June 18th, 2013

The Powerglide transmission is a two speed automatic made by General Motors. There are two versions of this transmission; one with a Chevy bell housing bolt pattern and another with a Pontiac / Buick / Oldsmobile bell housing bolt pattern.  This transmission was first put into production in 1950 as a cast iron transmission. In the early 1960’s they came out with an aluminum version of the transmission that stayed in production until 1973. The aluminum version is the one all racers use. The Powerglide transmission was used extensively throughout the General Motors line up and they ended up making millions of them.  Over the years, the Powerglide has become a very popular choice as the automatic transmission of choice for drag racing.

The Powerglide transmission is very popular in drag racing


There are a couple of reasons why this transmission has become so popular.

First: it is fairly compact and lightweight.

Second: they are very simple to work on and have a low rotating mass.

Third: with only two gears, they make for very consistent and repeatable quarter mile times.

Fourth: just about every part of this transmission can be upgraded with better aftermarket parts to make them bullet proof.

Here are some of the parts available to build a Powerglide to your racing standards:

After market transmission case: While the factory case will hold up to most applications, there are times when it will not. There is more than one company that makes aftermarket, heavy duty, reinforced replacement cases, including Dedenbear, ATI, JW Performance and others. Some of them even come with a bell housing that can be unbolted (the original cases were all one piece).

There is a large variety of aftermarket Powerglide racing cases available


Heavy duty planetary gear ratios: The factory planetary gear sets cannot handle serious horse power and are subject to exploding under racing use.  Luckily, there are aftermarket gear sets available that are built from stronger materials in both the stock gear ratios and performance oriented ratios. Those ratios include 1.65, 1.69, 1.76, 1.80 and 1.82. They are also available in both straight cut and helix-cut gear styles.

Special input and output shafts: The stock input and output shafts are very noticeable weak components in their stock configuration. Heavy duty versions of both parts are available in a material call 300M.

Transmission brakes: A transbrake is use in race cars to apply both the forward and reverse clutches at the same time. When the drag racing tree turns green the drive releases the reverse clutches which results in a very violent launch. Transbrakes are available in both forward and reverse patterns.

There are many gear ratios to choose from.


Extreme duty friction material: There are many different types of friction materials available for the Powerglide. They range from a stock style all the way up to carbon fiber style with many options available in between.

Adapters: Just because the Poweglide was originally a GM product doesn’t mean that it can’t be used behind other brands of motors. There are both adaptors and special bell housing available to put a Powerglide behind a variety of motors include those from both Ford and Chrysler.  Some even incorporate a flex plate safety shield.

While racing transmissions may be available from a variety of transmission rebuilders, I highly recommend you consider buying yours from a company that specializes in re-manufactured transmissions. These companies have better test equipment and are used to making transmissions with very tight tolerances.  They also come with a much better warranty. Remember, you can order your racing Powerglide any way you like when making the purchase from a re-manufacturing company. Everything from mild all the way up to super wild is available with just a simple phone call!

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