GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Monte Carlo 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T60-E 🢒 Case Extension Replacement

Removal Procedure
  1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Disconnect the right drive axle from the transaxle. Refer to Wheel Drive Shaft Replacement in Drive Axle.
  4. Remove the transaxle brace. Refer to Transmission Brace Replacement .
  5. Remove the vehicle speed sensor. Refer to Vehicle Speed Sensor Replacement .

    6. Object Number: 10517 Size: SH
  6. Remove the case extension housing bolts (5).
  7. Remove the case extension housing (6) with the axle seal and the O-ring (8) .

    8. Object Number: 10606 Size: SH
  8. Inspect the case extension (6) for the following conditions:
    9. • A damaged or porous sealing surface for the case extension seal
    • A damaged or porous sealing surface for the vehicle speed sensor
    • A damaged or porous sealing surface for the right drive axle oil seal
    • A damaged or porous sealing surface for the case extension housing
    • A damaged or worn differential carrier bushing or output shaft bearing
    • Damaged bolt holes
    • Inspect the drive axle seal and replace if necessary.

Installation Procedure
  1. If removed, install the drive axle seal. Refer to Front Wheel Drive Shaft Oil Seal Replacement .

    2. Object Number: 10517 Size: SH
  2. Install the case extension housing (6) with the axle seal and with the O-ring (8).

    3. 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.

  3. Install the case extension housing bolts (5).

    4. Tighten
    Tighten the case extension housing bolts (5) to 36 N·m (27 lb ft).

  4. Install the vehicle speed sensor. Refer to Vehicle Speed Sensor Replacement .
  5. Install the transaxle brace. Refer to Transmission Brace Replacement .
  6. Connect the right drive axle to the transaxle. Refer to Wheel Drive Shaft Replacement in Drive Axle.
  7. Lower the vehicle.
  8. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

    9. Notice: Do NOT overfill the transaxle. The overfilling of the transaxle causes foaming, loss of fluid, shift complaints, and possible damage to the transaxle.

  9. Adjust the fluid level.
  10. Inspect for completion of the repairs.
  11. Inspect for fluid leaks.