Great Performance Enhancers For The 4L60E Transmission In Your Impala SS

Posted by on Monday, November 18th, 2013

The 4L60E is a four speed automatic transmission made by General Motors. It is heavily based on one of GM’s first automatic overdrive transmissions, the 700R4. The main difference between the two are that the 4L60E is fully electronic and the 700R4 is not. The 4L60E was used in just about every full size car in the GM multiple brand lineup, including the Impala SS.

The Chevrolet Impala SS came equipped with the 4L60E automatic transmission


The Impala SS was a vehicle designed to fill a niche in the group of GM  high performance vehicles. The Impala is a full size car capable of hold six adults, and is largely based on the Chevrolet Capris. GM’s other performance cars, including the Corvette and Z28 Camaro, were really only designed to carry two people (although the Camaro had a back seat, it was so small it was impractical). When young men and women started having families, they quickly outgrew their Corvettes and Camaros. They still wanted a performance car, but it had to be more family friendly. Enter the Impala SS. The Impala SS was built for only a short time (1994 – 1996), but they have a hardcore following, even though they have been out of production for near two decades.

In stock form, the 4L60E does not live up to the Impala SS’ performance image. No worries; there are plenty of aftermarket parts that you can use to enhance the performance of your 4L60E transmission.  Let’s take a look at a couple of them.

Get a hand held tuner: Most handheld tuners will include provisions for modifying the characteristics of the 4L60E transmission. This is only possible because the transmission is electronically controlled by a number of electrical solenoids. A non-computer controlled transmission would require the installation of a shift kit.

A hand held tuner is a great way to enhance the performance of your 4L60E transmission


The modifications made with a handheld tuner will offer a number of performance benefits.  First, they will help increase the internal transmission line pressure. This will create more clamping force on the bands and clutches and help prevent them from slipping.  Modifications made with the tuner will also allow for quicker and firmer shifts, which will result in lower elapsed quarter mile times.

Install a performance torque converter: The stock, factory installed torque converter found in the Impala SS leaves a lot to be desired. It is a design compromise that is built to deliver the best fuel mileage. The stock converter has a low stall speed of around 1500 rpms. Because the Impala SS is such a heavy car, it really benefits from a higher stall speed torque converter. For dual purpose applications (street and strip), I recommend upgrading to a converter with a stall speed of around 2100 RPM. This will give you much better off-the-line performance without killing your gas mileage. Be sure that any performance torque converter you are considering comes with furnace brazed impellers and turbine fins.

A performance torque converter for your 4L60E equipped Impala SS should include furnace brazed fins


Sooner or later, due to high mileage or abuse, you will be faced with a decision to replace the 4L60E in your Impala SS. 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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