Low/Reverse Servo Assembly Replacement

Low/Reverse Servo Assembly Replacement

Removal Procedure





Warning

Ensure that the vehicle is properly supported and squarely positioned. To help avoid personal injury when a vehicle is on a hoist, provide additional support for the vehicle on the opposite end from which the components are being removed.

1. Position the vehicle on a hoist and raise the vehicle. Refer to Lifting and Jacking the Vehicle Service and Repair.
2. Remove the transaxle oil pan. Refer to Oil Pan Replacement 4T45-E - Automatic Transmission.
3. Remove the oil feed pipe-to-low/reverse servo assembly bolt.

Note: Remove servo cover bolts evenly to prevent damage to servo cover.

4. Remove the low and reverse band servo cover assembly bolts.
5. Pull the oil feed pipe away from the servo cover and remove the servo assembly.

Disassembly Procedure




1. Remove the piston pin assembly from the servo cover.
2. Remove the snap ring (70) from the servo pin.
3. Remove the piston (77) and the servo cushion springs (75)from the servo pin.
4. Remove the servo piston seals from the cover (78, 79).
5. Discard the servo piston seals.
6. Inspect all components for damage.
7. Inspect the fluid feed holes for the proper opening.
8. Inspect the bolt hole threads for debris or stripping.
9. Inspect the seal grooves for damage.
10. Clean and dry each component.

Assembly Procedure




1. Assemble the servo cushion springs (75) and the servo piston (77) onto the servo pin (76).
2. Install the snap ring (70) onto the servo pin in order to retain the servo cushion springs and servo piston.
3. Assemble new seals (78, 79) onto the servo piston and servo cover.
4. Assemble the servo piston assembly into the servo cover. Lubricate the piston seals with transaxle fluid in order to aid in assembly.

Installation Procedure





Note: Hand start and tighten the servo cover bolts evenly to prevent damage to the servo cover bore.

1. Install the servo return spring into the transaxle case.
2. Install the servo cover and piston assembly over the servo return spring.

Caution: Refer to Fastener Caution Fastener Caution.

3. Hand start and install the servo cover bolts and tighten to 12 Nm (9 lb ft).
4. Install the oil pan. Refer to Oil Pan Replacement 4T45-E - Automatic Transmission.
5. Lower the vehicle.
6. Remove the AIR. Refer to Transmission Fluid Level and Condition Check Transmission Fluid Level and Condition Check.
7. Add DEXRON(R) VI transaxle fluid or equivalent to the specified refill capacity.

* The bottom pan removal capacity is approximately 6.5 L (6.9 qt).
* The complete overhaul capacity is approximately 9 L (9.5 qt).
* The dry capacity is approximately 12.2 L (12.9 qt).

8. Start the engine, warm up the transaxle, and check for leaks.
9. Inspect for proper fluid level. Refer to Transmission Fluid Level and Condition Check Transmission Fluid Level and Condition Check.

Note: It is recommended that transmission adaptive pressure (TAP) information be reset.

Resetting the TAP values using a scan tool will erase all learned values in all cells. As a result, The ECM, PCM or TCM will need to relearn TAP values. Transmission performance may be affected as new TAP values are learned.

10. Reset the TAP values. Refer to Transmission Adaptive Functions Transmission Adaptive Functions.