This transmission was designed with the dream of bolting a 5 speed transmission directly to where a 4 speed came out of with no modification to the car while also gaining not only an overdrive gear, but also higher horsepower handling. The Mopar branch of the 5SR, otherwise known as the A855 transmission has been tested up to 750 foot pounds of torque and handles it without breaking a sweat.
From overhead our 1st gear looks similar to the stock Hemi 1st gear, but when looking at the tooth width you can see where the extra horsepower capabilities come into play.
Each transmission starts out with an aluminum case. Aluminum was selected because it is strong but lightweight compared to iron or steel.
Pictured below is the gear set in the 5SR transmission.
The 5SR transmission goes through detailed testing to make sure everything does exactly what it is supposed to and does it precisely the way it was designed to do it as soon as it leaves assembly. After assembly the transmissions are filled with a purpose engineered oil and testing is done on an in house test device to simulate operation in a vehicle to make sure it goes into each gear smoothly and runs within expected noise parameters.
Then while still filled with oil, each transmission is pressurized overnight to ensure there is no leaks before being drained and readied for shipping.