Shaft Service
Automatic transmission and transaxle shafts,
including input, output, and stator shafts, require little
service. Check seal ring grooves and bushing surfaces for
wear, scoring, and overheating. Inspect shaft splines for
wear or damage, Figure 17-9. Any shaft with worn or
damaged splines should be replaced. If you suspect that a
shaft is bent or warped, it can be checked with V-blocks
and a dial indicator as shown in Figure 17-10.
Planetary Gearset Service
Check the teeth of the planetary gears for wear, nicks,
and chipping. Figure 17-11 shows a gearset that has been
destroyed. Figure 17-12 shows a sun gear being inspected
for tooth damage. Slightly nicked gears can cause noises
and vibration, and eventually, they will fail completely.
Splines found on the gearset members should also be
checked for wear and damage. Check the clearance
between the planet gears and the planet carrier to deter-
406 Automatic Transmissions and Transaxles
Note: During inspection, it is not absolutely
necessary to check the soft parts, such as
gaskets, lip seals, O-rings, seal rings, and
friction discs. These parts are replaced during a
rebuild. Checking the soft parts, however, will often
help you to determine what caused the transmission
or transaxle to fail.
Check for snap
ring groove wear
Inspect for
worn splines
Check for debris
in oil feed Inspect oil
seal ring groove
Check for worn
bushing riding surface
Figure 17-9. After the transmission or transaxle has been
disassembled, check shaft splines, bearing journals, and ring
grooves for wear.
V-blocks
Dial indicator
Rotate
transmission shaft
Figure 17-10. Input and output shafts can be checked for
bends or warpage using V-blocks and a dial indicator. Never
attempt to straighten a bent or warped shaft. (Toyota)
Planet
carrier
Damaged
planet gears
Figure 17-11. Worn or damaged planet gears can result in a
noisy transmission or transaxle. Severely damaged gears will
strip off or jam, resulting in a no-drive condition. (BBU, Inc.)
Inspect all
gear teeth
closely
Figure 17-12. Gear teeth on all of the planetary gears should
be closely inspected for chips, cracks, scoring, and wear. Also,
check for worn snap ring grooves or bushings. Replace any
damaged gears. (DaimlerChrysler)