Mainshaft Inspection

Inspect the gear and bearing contact areas for wear and damage, then measure the mainshaft at points A, B, C, D, and E. If any part of the mainshaft is less than the service limit, replace it.
Standard:

A Ball Bearing Contact Area (Transmission Housing Side): 27.987-28.000 mm (1.1019-1.1024 in.)

B Distance Collar Contact Area: 31.984-32.000 mm (1.2594-1.2598 in.)

C Needle Bearing Contact Area: 38.984-39.000 mm (1.5348-1.5354 in.)

D Ball Bearing Contact Area (Clutch Housing Side): 27.977-27.990 mm (1.1015-1.1020 in.)

E Bushing Contact Area: 20.80-20.85 mm (0.8189-0.8209 in.)

Service Limit:

Fig 1: Inspecting Mainshaft Gear & Bearing With Specifications
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Inspect the runout by supporting both ends of the mainshaft. Then rotate the mainshaft two complete turns while measuring with a dial gauge. If the runout is more than the service limit, replace the mainshaft.
Standard: 0.02 mm (0.001 in.) max.

Service Limit: 0.05 mm (0.002 in.)

Fig 2: Inspecting Runout With Supporting Ends Of Mainshaft
Courtesy of AMERICAN HONDA MOTOR CO., INC.