GM Service Manual Online
For 1990-2009 cars only

5th/6th Gear Synchronizer


    Object Number: 1474823  Size: SH

    Important: Ensure that the hub slides easily.

  1. Apply lubricant GM P/N 89021806 (Canadian P/N 89021807) as shown in illustration. Install the following components into the 5th/6th synchronizer hub (124/118):
  2. • the 5th gear blocking ring (121b)
    • the 6th gear blocking ring (121a)

    Object Number: 1474824  Size: SH
  3. Apply lubricant to the blocking ring, driven gear and sleeve. Install the following components into the reverse gear (206):
  4. • the reverse gear insert (120) and the spring (195)
    • the reverse gear blocking ring (122)
    • the reverse driven gear (112)
    • the synchronizer sleeve (125)

1st/2nd, 3rd/4th Gear Synchronizer


    Object Number: 1504129  Size: SH
  1. Install the synchronizer insert and spring into the synchronizer hub. Press the spring and slide the insert in.

  2. Object Number: 1474821  Size: SH

    Important: When you service the synchronizers, retain them in the same order that they are removed. Keep the synchronizer components together and mark them to identify correct location.

  3. Apply lubricant to the cones and blocking rings. Align and install the following components into the 1st/2nd gear synchronizer hub (115/117):
  4. • the 1st gear synchronizer inner cone (96)
    • the 1st gear synchronizer outer cone (97)
    • the 1st gear outer blocking ring (98)
    • the 2nd gear outer blocking ring (98)
    • the 2nd gear synchronizer outer cone (97)
    • the 2nd gear synchronizer inner cone (96)

    Object Number: 1474822  Size: SH
  5. Apply lubricant to the blocking rings. Install the following components into the 3rd/4th gear synchronizer hub (116/118):
  6. • the 3rd gear blocking ring (104)
    • the 4th gear blocking ring (121)