Turn Up the Performance Of The 4L60E Automatic Transmission In Your Firebird

Posted by on Monday, November 25th, 2013

The 4L60E is a four-speed automatic transmission designed and produced by General Motors. It first went into production in 1992 and was finally phased out after the 2008 model year.  It saw wide spread use in the entire GM lineup, including a few modern muscle cars. Among those were the Chevrolet Camaro and the Pontiac Firebird.

The late model Trans Am came equipped with the 4L60E automatic transmission

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The Pontiac Firebird came in a number of trim levels, including the top of the line Trans Am.  The Trans Am has a cult like following and its owners are very loyal to the make and model. In stock form, the 4L60E is a decent transmission. Problems start occurring when the vehicle owners start modifying their motors to make more power. Without proper modifications, the 4L60E will not last long behind a modified high output motor.

Luckily, there are plenty of things you can do to match the performance of your transmission to the performance of your motor. Let’s take a look at a few of them.

I would first recommend the installation of a shift kit. The 4L60E will see a number of benefits from doing so. First, a shift kit will include parts and instructions for raising the internal line pressure of the transmission. This will result in more clamping force on the bands and clutches, helping prevent them from slipping and prematurely wearing out.

This is the 4L60E automatic transmission found in the Trans Am


Second, the kit will give you more manual control of the 4L60E transmission, allowing you to hold it in a single gear longer. This will help reduce your quarter mile elapsed times when drag racing. Third, the kit will cause the bands and clutches to fully apply quicker. This will give you the tire chirping performance many enthusiasts are after. It will also reduce excessive wear and heat buildup.

I would also recommend you consider upgrading your torque converter. The factory torque converter stalls somewhere around 1500 – 1600 rpms.  For better off the line performance and reduced quarter mile times, consider moving up to a 2100 – 2400 rpm stall converter. This will allow you to launch your car at a higher motor rpm, in a range in which the motor is producing more power. A true performance torque converter should include furnace brazed turbine and impeller fins, anti-balloon plates and a hardened drive tube.

It is highly advised that you install a shift kit in your 4L60E automatic transmission equipped Trans Am


When going with a higher-than-stock stall converter, it is also advised that you invest in an aftermarket transmission cooler. The higher the stall of a torque converter, the more heat it will make. Keep in mind that excessive heat is the number one killer of all performance automatic transmissions, so it’s important to keep the transmission temperature under control.

Sooner or later, due to high mileage or abuse, you will be faced with a decision to replace the 4L60E in your Pontiac Firebird or Trans Am. I highly recommend doing so with a re-manufactured transmission over one that was simply rebuilt. A re-manufactured transmission comes with a much better warranty; three years compared to an average 90 days for a rebuilt transmission. 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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