INSPECTION OF TRANSMISSION COM-
PONENTS
Reverse gears and idle gear
Inspect the chamfered edges (1) of gear teeth of the three gears-
driving and driven gears (of input shaft and countershaft) and idle
gear. If the edges are worn badly, replace the gears. Abnormal
noise of gear slipping in reverse drive is often due to worn tooth
edges of these gears.
Input shaft and its bearings
If any of input shaft gears is found with chipped or broken teeth, re-
place input shaft. Check each bearing by spinning its outer race by
hand to “feel” the smoothness of rotation. Replace the bearing if
noted to exhibit sticking, resistance or abnormal noise when spun
or rotated by hand.
Check spline (1) of input shaft for wear and damage. Replace if de-
fective.
Combination of gear and synchronizer ring
Fit ring to cone of the gear (top gear, or “third”, “second” or “low”
gear), and measure the clearance between the two at the peripher-
al teeth, as shown in below figure. If the clearance has reached or
exceeds the service limit, replace the worn part.
Inspect the external cone (of gear) and internal cone (of ring) for
abnormal wear. Be sure that the contact patterns on these surfaces
indicate uniform full-face contact, and that the surfaces are from
any wavy wear. A badly worn member must be replaced.
Proper synchronizing action on gear shifting can be expected
when the ring-to-gear clearance and the condition of cone sur-
faces, among other things, are satisfactory.
1. Checking contacting surface
7A-12
MANUAL TRANSMISSION (4-SPEED)
Clearance between
Standard
Service limit
Clearance between
gear and ring
0.8 – 1.2 mm
(0.03 – 0.05 in.)
0.5 mm
(0.02 in.)
