Mainshaft and Synchronizers

Clean
- All parts in a suitable solvent and air dry.

Important
- Do not spin dry ball bearings.

Inspect
1. Gears for:
- Cracks.
- Nicks.
- Chipped gear teeth or high spots (a small shiny spot on the gear teeth mating surface) that could cause gear noise.

2. Related surfaces on the gears like thrust faces and bearing surface diameters.
3. Synchronizer sleeves for:
- A sliding fit on the synchronizer hubs.
- Used output shaft hubs will have a slip fit.

4. Synchronizer springs and keys for:
- Damage.

5. Synchronizer rings for:
- Excess wear.

6. Synchronizer clutching teeth for:
- Wear
- Scuffing.
- Nicks.
- Burred or broken teeth.

7. Speed gear clutching cones for:
- Synchronizer ring metal transfer.

8. All gear teeth for:
- Excess wear.

9. Bearings and bearing surfaces for:
- Nicks.
- Burrs.
- Bent cages.
- Wear.

10. Lubricate all bearings and check for rough rotation.
- If scuffed, nicked, burred, scoring, or synchronizer ring metal transfer conditions cannot be removed with a soft stone or crocus cloth, replace the component and inspect mating parts.
- Lubricate all components as assembly progresses. Use lubricant Synchromesh Transmission Fluid GM P/N 9985648 or equivalent.