As the crew at PCS explains it: "The primary factor separating the modern electronic automatic transmission from yesterday's hydro-mechanical automatic transmission is the speed and complexity of the logic used for transmission behavior. The hydro-mechanical automatic transmission of yesterday could only make its decisions based on throttle position, engine load, and driveshaft speed. Whereas the TCU can use these inputs as well as torque converter speed, engine speed, wheel speeds, traction control parameters, electronic throttle position, fluid temperature, engine temperature, brake pedal actuation, forward and lateral acceleration, as well as several other parameters. The TCU can also utilize manual shifting operation and provide altered transmission behavior for special conditions (road race, drag race, dynamometer, snow, towing)."

For those looking for a straightforward, easy-to-live-with transmission controller, PCS offers the Simple Shift. A laptop is not required to install the Simple Shift and it will completely control shift points, shift firmness, and torque converter lockup. Transmission shift points are adjusted by dials on the end of the control unit and diagnostic capabilities are communicated by flashing LEDs that also indicate what gear the transmission is in and whether or not the torque converter is locked. For those who want more adjustment options the Simple Shift tuner is also available. The handheld unit can remain connected to the Simple Shift or be removed when programming is complete. Also available from PCS is the TCM-2000. Similar to all their controllers, the TCM-2000 features dual calibrations that allow the driver to pick from two distinctly different transmission operating modes (sport mode, tow-haul mode, and so on) with programmable shift points, shift firmness, and torque converter lockup tailored to each application. A CAN interface (controller area network, which lets multiple computers to talk to one another) allows the TCM-2000 to be seamless, used with CAN-based vehicles or ECUs, and also simplifies the connection to a PCS Paddle Shifter or GSM-2100 Gear Select Module.

To put shifting at your fingertips, PCS offers the GSM Push Button Shifter that replaces the shift lever and linkage with a small touch-pad control module and sealed actuator. Thanks to its design the GSM control module can be surface or flush-mounted and is small enough to fit in consoles, dashes, door panels, or even armrests. Each button is recessed to avoid inadvertent touches and brightly backlit for darker environments. An easy-to-read display shows you what gear you're in. Standard control modules utilize a PRND configuration along with plus and minus buttons for shifting up or down.

Another unique shifting option is the PCS Paddle Shifter. Designed to provide the look and feel of an OEM system, it will bring out the Ferrari Formula 1 driver in anyone, it's that cool. Easily installing behind any aftermarket 5-, 6-, or 9-bolt steering wheel, the paddle shifter communicates with the transmission control unit via a wireless receiver module that plugs into the PCS transmission control unit's wiring harness.

As if the paddle shifters aren't cool enough, the optional display allows the driver to view an array of data, including current gear, vehicle speed, coolant temperature, converter lockup, engine rpm, turbine rpm, transmission slip, manifold pressure, transmission temp, line pressure, and driveshaft rpm.

Installation of the Simple Shift is uncomplicated. Mount the unit, hook up the wires, and you're ready to go. The output from the TCU plugs into the factory socket on the transmission, the remaining wires are for signals to the TCU—some aren't used while others are, depending on the application.

6. One way to have the best of both the performance and economy worlds is a Gearstar lockup converter with slightly increased stall speed. Note the dual bolt pattern.

7. All Gearstar transmissions are built in this spotless facility by one technician from start to finish. The individual who puts the transmission together answers any tech questions.

8. From years of experience the team at Gearstar has developed parts to improve OEM transmissions. Here is a direct drum on the left and a reverse drum on the right, both are equipped with improved clutch components for increased torque capacity and longevity.

9. Gearstar has found and improved weak spots in every transmission they offer. Here is a hardened 4R70W main shaft on the left compared to a stock shaft on the right. Again, the goal is increased torque capacity and reliability.

10. Before they are shipped, each Gearstar transmission is thoroughly tested on the in-house dyno. Transmissions are shipped with fluid, the proper dipstick, and a cooler.

11. The clutch frictions and steels in any automatic transmission are critical. For performance applications, improved materials, such as those shown here, are a must.

12. Also incorporated in all Gearstar transmissions are the latest factory updates available. Here is an early production roller clutch on the left compared to the later, improved version on the right.