Modify the Powerglide Transmission in Your 1962 Impala for Performance

Posted by on Tuesday, May 27th, 2014

The Powerglide was one of General Motors’ first automatic transmissions. It first went into production in 1950 and lasted through the end of the 1973 model year. All Powerglides are two-speed transmissions (compared to a modern automatic transmission that has up to eight speeds). At first the Powerglide was produced from heavy cast iron. In 1962, GM switched over to producing the Powerglide made of lightweight aluminum. This transmission was used extensively throughout the GM line, and could be ordered as an option in the following vehicles: the Bel Air, the full line of light duty pickup trucks, the Impala, and many other vehicles from Cadillac, Buick, Pontiac, and Oldsmobile.

A 1962 Impala, which featured a Powerglide transmission.

One of the most popular applications for the Powerglide was in the Chevrolet Impala. Many were produced over the lifespan of this vehicle. Over the years, the 1962 version of the Impala has become the must-have model of the group. Its gorgeous lines make it highly desirable. It was also no slouch when it came to performance. The 327 cubic V8 made good power, but it was the optional 409 that really made this car fly.

As we all know, performance enthusiasts can’t leave their motors alone. They are always modifying them to make more power. The problem is that the Powerglide, in its stock configuration, can’t hold up to a lot of power. Here are a few things you can do to increase the performance of the Powerglide in your 1962 Impala:

Install a large, performance transmission cooler: Heat is the number one source of all automatic transmissions failures, regardless of the age, brand, or model. The Powerglide is no exception. This transmission is designed to operate at a maximum temperature of about 200 degrees. For every 20 degrees you go over beyond  limit, you risk cutting the life of the transmission by a factor of two. I advise that you buy the largest transmission cooler that will fit your Impala (transmission coolers are universal in design and come in many shapes and sizes). Be sure to mount it in a location that will see plenty of air flow. If that is not possible, consider buying a transmission cooler that has its own built-in electric fan.

Install a valve body modification kit: This is a must-have item for serious performance. Sometimes these kits are better known as shift improver kits. A shift kit will offer a number of benefits to your Powerglide. First, it will give you more manual control over your automatic transmission. It will allow you to hold it in one gear for a longer time (before it up shifts on its own), and will also allow you to downshift at almost any speed. Second, it will reduce the time it takes for the clutches and bands to fully apply. Finally, it will help reduce wear and excessive heat buildup.

Use synthetic automatic transmission fluid: Synthetic fluids behave much better under adverse conditions, unlike their organic cousins. Organic fluids will start to break down and turn to varnish at temperatures as low as 240 degrees. This will not happen as easily with synthetic fluids. While synthetic fluids are more expensive to purchase, they will save you money in the long run by reducing internal wear and extending the mileage interval between transmission fluid changes.

Purchase a high performance converter: The stock torque converter in your Impala has a fairly low stall speed around 1500 rpms. While good for fuel mileage, it does nothing to help the Impala’s performance. By installing a torque converter with a higher stall speed, you allow the car to launch at a higher rpm, where the motor is making more torque. When shopping for a performance torque converter, make sure it has these three things: furnace brazed impeller fins, a hardened drive tube, and an anti-balloon plate.

Sooner or later, due to high mileage or abuse, you will be faced with a decision to replace Powerglide transmission in your 1962 Chevy Impala. I highly recommend doing so with a re-manufactured transmission over one that was simply rebuilt. A re-manufactured transmission will include major internal modifications and upgrades designed to make it both stronger and more durable. A rebuilt transmission will not include this feature. A re-manufactured transmission also comes with a much better warranty; three years compared to an average 90 days for a rebuilt transmission. And in the rare event that you need to contact the company that re-manufactures transmissions, they are just a quick phone call or email away!

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