Mainshaft and Synchronizers. Chevrolet Export Chevy P42 Commercial Chassis 1999

For 1990-2009 cars

1. Clean all the parts in a suitable solvent. Air dry all the parts.

Important: Do not spin the bearings without a lubricant.

2. Lubricate the mainshaft bearings with the proper transmission lubricant.
3. Check the bearings for rough rotation.
4. Inspect the mainshaft gears for the following conditions:

• | Cracks

• | Nicks

• | Chipped gear teeth

• | High spots (small-shiny spots on the gear teeth mating surface) that could cause gear noise

5. Inspect related gear surfaces like thrust faces and bearing surface diameters.
6. Inspect the synchronizer sleeves for a sliding fit on the synchronizer hubs. The synchronizer hubs must have a force fit on the mainshaft splines.
7. Replace a synchronizer hub that does not require a force fit on the mainshaft splines.
8. Inspect the synchronizer springs and the keys for damage.
9. Inspect the synchronizer rings for excess wear.
10. Inspect the synchronizer clutching teeth for the following conditions:

• | Scuffs

• | Nicks

• | Burrs

• | Damage

11. Inspect the mainshaft drive gear clutching cones for synchronizer ring metal transfer.
12. Inspect all the gear teeth for excess wear.
13. Remove nicks and burrs with a soft stone or a crocus cloth.
14. Replace any components that are bent or show signs of excessive wear. Inspect the mating parts.
15. Inspect the bearings and the bearing surfaces for the following conditions:

• | Nicks

• | Burrs

• | Bent cages

• | Wear

• | Overheating

• | Scoring

• | Pitted condition