GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 STS 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 6L50/6L80/6L90 🢒 Case Extension and Gasket Replacement

Case Extension and Gasket Replacement 6L50

Tools Required

J 45012 Holding Fixture

Removal Procedure
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the exhaust system. Refer to Exhaust System Replacement .
  3. Remove the drive shaft. Refer to Rear Propeller Shaft Replacement .
  4. Support the transmission with a suitable jack.
  5. Remove the transmission mount assembly. Refer to Transmission Mount Replacement .

    6. Object Number: 1850663 Size: SH
  6. Install the propeller shaft flange holding fixture J 45012 .

    7. Notice: Do not reuse the flange nut. Reusing the flange nut may cause damage to the transmission.

  7. Remove and discard the propeller shaft flange nut.
  8. Remove the propeller shaft flange.

    9. Object Number: 1850668 Size: SH
  9. Remove the case extension housing bolts.
  10. Remove the case extension housing.
  11. Remove the case extension housing seal.

Installation Procedure

    Object Number: 1850668 Size: SH
  1. Install the case extension housing seal.
  2. Install the case extension housing.
  3. Install by hand the case extension housing bolts.

    4. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1850669 Size: SH
  4. Secure the case extension housing bolts in the specified sequence.

    5. Tighten
    Tighten the bolts to 50 N·m (37 lb ft).


    Object Number: 1850665 Size: SH
  5. Install the prop shaft flange.

    6. Notice: Stake the flange nut onto the output shaft. Use the two staking grooves on the shaft to locate the staking points. Failure to stake the flange nut may result in damage to the transmission.

    Important: Use a NEW propeller shaft flange nut.

  6. Install the NEW propeller shaft flange nut.

    7. Tighten
    Tighten the nut to 105 N·m (77 lb ft).

  7. Remove the propeller shaft flange holding fixture J 45012 .
  8. Install the transmission mount assembly. Refer to Transmission Mount Replacement .
  9. Remove the transmission jack.
  10. Install the drive shaft. Refer to Rear Propeller Shaft Replacement .
  11. Install the exhaust system. Refer to Exhaust System Replacement .
  12. Lower the vehicle.

Case Extension and Gasket Replacement 6L80


Object Number: 1657036 Size: MF

Callout

Component Name

Important: The extension housing and drive shaft flange (yolk) on this vehicle are serviced as a complete assembly. The drive shaft flange seal is a dust shield used to protect the sealed drive shaft flange bearing that is pressed into the extension housing. The drive shaft flange is pressed into the drive shaft flange bearing, and is not serviceable. The extension housing should NOT contain any transmission fluid. If transmission fluid is present in the extension housing, replacement of the output shaft seal is necessary. Refer to Transmission Output Shaft Seal Replacement .

Preliminary Procedures

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the exhaust system. Refer to Exhaust System Replacement .
  3. Remove the drive shaft. Refer to Rear Propeller Shaft Replacement .
  4. Support the transmission with a suitable jack.
  5. Remove the transmission mount assembly. Refer to Transmission Mount Replacement .

1

Case Extension Housing Bolt (Qty: 6)

Notice: Refer to Fastener Notice in the Preface section.

Tighten
50 N·m (37 lb ft)

2

Case Extension Housing Assembly

Tip

    • Serviced as a complete assembly as shown.
    • There is no gasket or seal between the extension housing and transmission case.