Inspection of components

Inspection of components

Before inspecting the various parts removed from the gearbox casing thoroughly wash all components and blow dry using a compressed air jet and then proceed as follows:

1. Thoroughly inspect the gearbox casing to ensure that it is not cracked and that the bearing seats are neither worn or damaged so allowing the bearing outer ring to rotate during the normal operation.
2. Thoroughly check the ballbearings to ensure that they are in perfect condition and that both radial ply and axial play is not excessive. The maximum permissible bearing play is as follows:

Front bearings of primary shaft layshaft:

(a) Sideways .002 inch

(b) Endwise .017 inch

Primary shaft rear bearing:

(a) Sideways .002 inch

(b) Endwise .016 inch

Hold the bearings firmly by the outer race and gently rock the inner race backwards and forwards. The sliding action produced should be free and silent. If any roughness is felt then the bearings must be renewed. Check the roller bearings by inspecting the condition of the rollers as well as the outer and inner races. Always fit new bearings if there is any doubt as to their efficiency.

3. Check the layshaft and the primary shaft between centres and using a dial gauge ensure that there is no distortion. The out of true reading for bearing seats should be less than .0008 inch. Inspect the splines and ensure that the side and outerfaces are not indented. Replace if there are signs of wear. Also inspect the reverse shaft to ensure that it is perfectly smooth and not showing signs of pitting or partial seizure.
4. Carefully inspect all gear teeth for signs of excessive wear or damage. The contact faces must be smooth and show no signs of indentation marks. Also check that the backlash between the gears, when correctly mounted on the surface plate is not greater than .0039 inch. The maximum wear limit is .0079 inch. Check that the quick engagement front teeth of the second-, thirdand fourth-speed gears are not damaged or excessively worn. Renew if there are signs of gearchange lever misuse.
5. Inspect the sliding sleeves and the relevent hubs, ensure that all the working surfaces are perfectly smooth. The clearance between the mating parts should not be greater than .0059 inch. Also inspect the meshing teeth and ensure that they are in good condition.
6. Check that the gear shifting selector forks are not distorted and that the striker rods freely slide in their seats in the gearbox casing.
7. Carefully inspect that all the oil seals are in perfect condition and if there is any doubt they should be renewed.
8. Inspect the striker rod locking balls and the safety rollers and ensure that they slide freely in their seatings. Also check the ball load spring efficiency and if this shows signs of weakness then it should be renewed. Any faults with these items will cause difficulty in engaging gears or autodisengagement during engine acceleration.