5R55S Level 10 Transmission Build - Animal House

Ford hit the ball out of the park when it developed the 5R55S automatic tranny for the S197 Mustang. Instead of the normal three gears with an overdrive to knock down the rpm, the 5R55S showcases four forward gears and an overdrive gear, making it a five-speed automatic. For the performance-minded folks, the five-speed sports a super-low 3.25:1 First gear for brisk acceleration. This makes it easier to aggressively move the Mustang's increased weight.

As is the case with most automatic trans-missions, making one live behind a juiced-up powerplant requires upgraded components that not only improve reliability, but also allow the transmission to accept and distribute all of the engine's power to the rear wheels. Enter Level 10 Transmission's PTS Animal transmission kit.

According to Pat Barrett, owner of Level 10, a kit of this type is needed to get the most power from the engine to the ground. "The PTS Animal transmission kit is designed to calibrate the transmission to work with a modified or super-charged engine," he says. "The kit changes the factory slushbox-type shifts to firm, yet not harsh, shifts at light throttle, and firmer shifts when the thottle is held wide open."

Having already developed a PTS kit for diesel-equipped Ford trucks, Level 10 saw the need for a transmission kit that would enable the 5R55S to live behind a supercharged or otherwise-modified Three-Valve. According to Barrett, there's much more to this kit than just the hardware. "The kit comes with Animal clutches and bands, along with a new pump, converter, and solenoid," he says. "The most important part of the kit, however, is the tuner that comes with a new calibration for the transmission."

With older-style transmissions, improving the tranny's shifting ability was handled manually via a valvebody rerouting the trans fluid as needed. With the new electronically controlled transmissions, improving the transmission's shift characteristics is done by changing the calibration for the trans via the ECM.

"The factory transmission is calibrated for soft, lazy shifts," Barrett says. "The calibration is so close that any modifications to the engine's power output causes the transmission to slip. The 5R55S needs calibration of the ECM, transmission, and torque converter to get the power to the wheels. Without combining the engine management to the transmission calibration, you won't have success with getting the car to use all of the available power you've put into it."

In addition to coming with a calibration change for the transmission, the kit also includes upgraded clutches, bands, and Level 10's PTS billet torque converter, PTS Super Pump, and PTS Super Solenoid.

The improved shift characteristics are attributed to the new calibration, which works well with the Super Solenoid. This solenoid is an upgraded component that allows the converter to lock up sooner, along with utilizing the calibrations firmer shift characteristics. The factory converter will allow only a certain amount of torque and power through it. Any more power than the converter is set up to handle is bled off by the converter slipping. Thus, heat in the converter and the trans fluid is built, and power output and reliability is hurt. The converter is upgraded to lock up quicker and utilize the extra power present without bleeding it off. Also helping reliability by improving fluid flow through the transmission is the Super Pump. This pump supplies more trans fluid than the stock pump, meaning the trans will run cooler and live longer.

Other major components to the kit are the internal clutches and bands, as well as the converter. "The difference between the clutches and bands is that the stock parts give you luxury-soft shifts," Barrett says. "The Animal clutches and bands can hold up to three times more power than the factory pieces are rated for, giving you the ability to get more power to the tires while letting the trans operate at a higher reliability level."

The converter is also a trick piece. According to Barrett, the factory torque converter has a drive plate that is bolted to the torque converter. It's the drive plate that's bolted to the flywheel, and not the converter itself. What this means is that a high-priced specialty tool is needed to align the plate to the torque converter. In addition, this is an inherent weakness in that the drive plate is prone to breakage, as well as being difficult to align.