Methods for improving the operation of transmissions for motor vehicles

A method for modifying an automotive transmission including a lockup control valve plunger for moving a lockup control valve element reciprocatingly in a lockup control valve bore, means for applying a hydraulic pressure to said lockup control valve for moving said lockup control valve element and said lockup control valve plunger in said lockup control valve bore, and an exhaust for exhausting hydraulic pressure from said lockup control valve bore, the steps of said method including:

• removing a bushing associated with the lockup control valve plunger and replacing said lockup control valve plunger and said bushing with a wider lockup control valve plunger having an outer surface substantially abutting against the inner surface of the lockup control valve bore for preventing cross-leaks of hydraulic fluid between said means for applying hydraulic pressure and said exhaust in said lockup control valve bore.

A method for modifying the operation of a factory installed A750E, A750F, or A761E automotive transmission having a control lockup relay valve element reciprocatingly movable in a control lockup relay bore in response to means for applying hydraulic pressure, and an exhaust in said control lockup relay bore for exhausting hydraulic pressure from the control lockup relay bore, the steps of said method including:

• widening said control lockup relay bore of said factor installed automotive transmission, and
• replacing said control lockup relay valve element of said factory installed automotive transmission with a widened control lockup relay valve element conforming to said widened control lockup relay bore for preventing cross-leaks of hydraulic fluid from said means for applying hydraulic fluid and said exhaust in said control lockup relay bore for maintaining hydraulic pressure applied to said control lockup relay valve element above a predetermined pressure value during operation of said automotive transmission.

A method for modifying the operation of a factory installed A750E, A750F or A761E automotive transmission including a lockup control valve plunger for moving a lockup control valve element reciprocatingly in a lockup control valve bore, means for applying a hydraulic pressure to said lockup control valve for moving said lockup control valve element and said lockup control valve plunger in said lockup control valve bore, and an exhaust for exhausting hydraulic pressure from said lockup control valve bore, the steps of said method including:

• removing a bushing associated with the lockup control valve plunger and replacing said lockup control valve plunger and said bushing of said factory installed A750E, A750F or A761E automotive transmission with a wider lockup control valve plunger having an outer surface substantially abutting against the inner surface of the lockup control valve bore for preventing cross-leaks of hydraulic fluid between said means for applying hydraulic pressure and said exhaust in said lockup control valve bore.