Forward Servo Replacement. GMC Truck GMC C Sierra

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2005 🢒 GMC C Sierra - 2WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L80-E/4L85-E 🢒 Forward Servo Replacement

Removal Procedure

Remove the transmission filter. Refer to Automatic Transmission Fluid and Filter Replacement .
Remove the forward servo cover bolts, cover, and gasket.
Remove the following parts:

3.1.	Forward servo piston pin (5)

3.2.	O-ring seal (4)

3.3.	Servo piston (3)

3.4.	Retainer (2)

3.5.	Piston spring (1)

Installation Procedure

Install the following parts:

•	Piston spring (1)

•	Retainer (2)

•	Servo piston (3)

•	O-ring seal (4)

•	Forward servo piston pin (5)

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the forward servo gasket, cover, and bolts.

Tighten
Tighten the bolts to 24 N·m (18 lb ft).

Install the transmission filter. Refer to Automatic Transmission Fluid and Filter Replacement .

Important: 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 engine control module (ECM), powertrain control module (PCM) or transmission control module (TCM) will need to relearn TAP values. Transmission performance may be affected as new TAP values are learned.

Reset the TAP values. Refer to Transmission Adaptive Functions .