Operation CHARM: Car repair manuals for everyone.

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 and for the hubs to have a force fit on the mainshaft splines. Replace the hub(s) if they do not require a force fit on the mainshaft.
4. Synchronizer springs and keys for:
- Damage
5. Synchronizer rings for:
- Excess wear.
6. Synchronizer clutching teeth for:
- Wear.
- Scuffed.
- Nicked.
7. Speed gear clutching cones for:
- Synchronizer ring metal transfer.
8. All gear teeth for:
- Excess wear.
- The black phosphate coating will develop wear patterns. This is a normal condition.
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 or equivalent.