- Clean all the parts in a suitable solvent. Air dry all the parts.
 
Important: Do not spin the bearings without a lubricant.
- Lubricate  the mainshaft bearings with the proper transmission lubricant.
 
- Check the bearings for rough rotation.
 
- Inspect the mainshaft gears for the following conditions:
 
| •  | High spots (small-shiny spots on the gear teeth mating surface)
that could cause gear noise | 
 
- Inspect related gear surfaces like thrust faces and bearing surface
diameters.
 
- Inspect the synchronizer sleeves for a sliding fit on the synchronizer
hubs. The synchronizer hubs must have a force fit on the mainshaft splines.
 
- Replace a synchronizer hub that does not require a force fit on
the mainshaft splines.
 
- Inspect the synchronizer springs and the keys for damage.
 
- Inspect the synchronizer rings for excess wear.
 
- Inspect the synchronizer clutching teeth for the following conditions:
 
- Inspect the mainshaft drive gear clutching cones for synchronizer
ring metal transfer.
 
- Inspect all the gear teeth for excess wear.
 
- Remove nicks and burrs with a soft stone or a crocus cloth.
 
- Replace any components that are bent or show signs of excessive
wear. Inspect the mating parts.
 
- Inspect the bearings and the bearing surfaces for the following
conditions: