GM Service Manual Online
For 1990-2009 cars only
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the extension housing from the transmission case. Refer to Extension Housing Removal .

  3. Object Number: 166342  Size: SH
  4. Remove the 2 speedometer drive gear retaining rings (1) from the transmission output shaft (3).
  5. Remove the speedometer drive gear (2).
  6. Inspect the speedometer drive gear (2) for abnormal wear or damage. Replace the drive gear, if necessary.