Methods and systems for improving the operation of transmissions for motor vehicles
The hydraulic circuitry of the factory installed automotive automatic transmission of the General Motors Corporation identified as the Allison 1000 and 2000 Series is modified to include a new return spring to decrease clutch pressure and mainline pressure so as not to exceed a predetermined pressure to reduce the time to complete an upshift, to replace the main regulator valve spring to increase main line pressure at road speed based on road conditions, and to provide a new valve with an internal exhaust circuit operatively associated with the TCC (Torque Converter Clutch) to lower balance circuit pressure resulting in the increase of converter clutch apply pressure. The methods and systems for modifying the factory installed transmissions improve the overall operation and efficiency of the transmission during operation of the motor vehicles in which the transmissions are installed.
1. A method of modifying a factory installed automatic automotive transmission having a solenoid controlled by a vehicle onboard computer for applying pressure to a first end of a trim valve for moving said trim valve in a first predetermined direction, a factory installed return spring applying a resilient force to a second opposite end of the trim valve to oppose said movement of the trim valve in said first predetermined direction, a check ball seated in a seat for controlling balance oil pressure applied to said second end of said trim valve for further opposing said movement of said trim valve in said first predetermined direction, wherein the steps of said method include:
replacing said factory installed return spring with a different return spring having a spring characteristic which controls main pressure of the hydraulic circuit to not exceed a predetermined value less than the main pressure of the factory installed transmission for decreasing the time for completing an upshift to a predetermined range of time less than that of the automatic automotive factory installed transmission;
said factory installed automatic automotive transmission further including a main mode line solenoid in fluid communication with a main regulator valve, and a factory installed main regulator valve spring arranged to exert a resilient force on a balance end of the main regulator valve, wherein the steps of said method further include:
replacing said factory installed main regulator valve spring with a different main regulator valve spring having a spring characteristic which raises main mode line solenoid pressure to a predetermined value exceeding that of the factory installed automatic automotive transmission based on driving conditions.
2. The method as claimed in claim 1 , wherein the step of selecting the return spring includes selecting the return spring so that main line solenoid pressure is raised above 150 pounds per square inch based on driving conditions.
3. The method as claimed in claim 1 , wherein the step of selecting the return spring includes selecting the return spring so that main line solenoid pressure is selected to control main pressure of the hydraulic circuit so that the range of time to complete an upshift is between 0.6-0.7 seconds.
4. The method as claimed in claim 1 , wherein said predetermined value of said main mode line solenoid pressure is above 150 pounds per square inch.