GM Service Manual Online
For 1990-2009 cars only

1st/2nd Synchronizer


    Object Number: 1955732  Size: SH
  1. Check the synchronizer assembly scribe marks for correct positions.

  2. Object Number: 1956859  Size: SH
  3. Install the synchronizer sleeve (1) to the hub (2) (align the key openings in the hub (2) with the cuts in the synchronizer sleeve (1)).
  4. Install the keys (3) with the slots facing the hub (2).

  5. Object Number: 1956857  Size: SH
  6. Assemble the first spring (1) (assemble the spring tang to one of the key slots in the synchronizer assembly (2)).
  7. Assemble the second spring (3) (assemble the spring tang on the same key but in the opposite direction).

3rd/4th, 5th/6th Synchronizers


    Object Number: 1955732  Size: SH
  1. Check the synchronizer assembly scribe marks for correct positions.

  2. Object Number: 1956859  Size: SH
  3. Install the synchronizer sleeve (1) to the hub (2) (align the key (3) openings in the hub (2) with the cuts in the synchronizer sleeve (1)).
  4. Install the keys (3) with the slots facing the hub (2).

  5. Object Number: 1956857  Size: SH
  6. Assemble the first spring (1) (assemble the spring tang to one of the key slots in the synchronizer assembly (2)).
  7. Assemble the second spring (3) (assemble the spring tang on the same key but in the opposite direction).

Reverse Synchronizer


    Object Number: 1955732  Size: SH
  1. Check the synchronizer assembly scribe marks for correct positions.

  2. Object Number: 1956859  Size: SH
  3. Install the synchronizer sleeve (1) to the hub (2) (align the key (3) openings in the hub (2) with the cuts in the synchronizer sleeve (1)).
  4. Install the keys (3) with the slots facing the hub (2).

  5. Object Number: 1956857  Size: SH
  6. Assemble the first spring (1) (assemble the spring tang to one of the key slots in the synchronizer assembly (2)).
  7. Assemble the second spring (3) (assemble the spring tang on the same key but in the opposite direction).

  8. Object Number: 1956870  Size: SH
  9. Install a new synchronizer key retainer (1) with the key retainer tangs over the synchronizer keys.