Overdrive Servo

4R70E/4R75E

Overdrive Servo





Removal

1. WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in Fire Suppression System. Failure to follow the instructions may result in serious personal injury Procedures.

Remove the main control valve body. For additional information, refer to Main Control Valve Body Main Control Valve Body.

2. NOTE: If the Servo Piston Remover/Installer tool is not available, extreme care must be taken. Spring pressure will force Overdrive (O/D) servo piston assembly out of case. Case bore damage may result from trying to pry on O/D servo internal retaining ring.

Using the Servo Piston Remover/Installer, compress the servo spring to remove the O/D servo retaining ring.





3. Remove the O/D servo piston and return spring.





Installation

1. Install the O/D servo piston assembly.

1. Install the O/D servo piston return spring.

2. Install the O/D servo piston assembly.





2. Use the Servo Piston Remover/Installer to install the O/D servo piston retaining ring.





3. Install the main control valve body. For additional information, refer to Main Control Valve Body Main Control Valve Body.

4. WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to Fire Suppression System. Failure to follow these instructions may result in serious personal injury Procedures.

If equipped with a fire suppression system, repower the system.