Chapter 17 Rebuilding Automatic Transmissions and Transaxles 421
The clutch packs are among the most critical parts of
the transmission. They should be carefully inspected and
serviced. Disassemble the clutch packs and inspect the
plates for wear. The friction discs are usually replaced as
part of an overhaul. The steel plates are often replaced.
Check the bands for wear, cracking, or burning.
Defective bands should be replaced. Band servos should
be disassembled, cleaned, and inspected. After the instal-
lation of new seals, the servos are ready to be reinstalled.
Accumulators are rebuilt in the same manner as servos.
The one-way clutches should be checked to ensure
that they turn in one direction only. Planetary gearsets
should be checked for obvious defects, such as chipped
teeth. Also, check the bushings, bearings, and washers at
all locations in the transmission.
Check the transmission/transaxle shafts. Inspect the
input and output shafts for wear, bending, or warpage. Also
check all the case parts, such as screens, valves, and seals,
for wear and damage. Seals should always be replaced.
To reassemble the transmission or transaxle, start by
soaking all new friction discs and bands in transmission
fluid. Then, install the output shaft, rear planetary gearsets,
clutches, bands, and other components at the rear of the
case. Remember to reinstall all snap rings in their original
positions. Then, install the center support, if the transmis-
sion is equipped with one.
Install the front planetary gearsets and clutches as
complete assemblies, as required. Measure the assembled
height to ensure proper assembly. Install any bands or
case-mounted clutches. Then, install the oil pump. Check
the transmission endplay and make sure that all shafts turn.
Install the governor on the output shaft or in the case,
as applicable. Then, install the extension housing and
other output shaft parts. Install the drive chain or transfer
gears as necessary.
Install the servos and adjust the bands. Also install
any case-mounted accumulators, electrical switches, and
other case parts. Then air pressure test the transmission.
Install parts that are installed inside the oil pan, such as the
valve body, spacer plates, check balls, filter, etc. Then,
install the oil pan.
Check the converter for wear or internal damage, and
then install it. Make sure the converter is installed properly
on the transmission shafts and the pump drive hub (when
used) is fully engaged in the front pump.
Review Questions—Chapter 17
Please do not write in this text. Place your answers on
a separate sheet of paper.
1. When rebuilding an automatic transmission, you
should work on one _____ at a time, so that parts are
not mixed up.
2. Before disassembly, clean the _____ of the transmis-
sion or transaxle.
3. What can be learned from inspection of the oil pan
and its contents?
4. Does the presence of a few aluminum particles in the
oil pan mean that the transmission or transaxle is
severely damaged? Why?
5. It is usually easier to remove the front pump seal with
the _____ still installed.
6. A _____ _____ _____ may be installed on the back of
some pumps. In this case, a set of _____ and _____
will be found directly behind the pump.
7. Many clutch packs and planetary gears are held in
place by _____ _____.
8. During the rebuilding process, gaskets, seals, and fric-
tion discs should be replaced:
(A) in all cases.
(B) only if obviously damaged.
(C) only if removed.
(D) None of the above.
9. Leopard spotting is a sign of excessive _____.
10. What visual signs indicate that a clutch pack has been
slipping?
11. Some technicians _____ steel plates before rein-
stalling them. This removes the _____ surface.
However, it is often cheaper to install _____ plates.
12. If clutch clearance is too _____, the clutch pack may
not apply tightly and may slip.
13. To remove a CVT belt, use a special tool to move the
drive pulley to the completely _____ position.
14. Badly scored pumps can often be spotted by a _____
inspection. Pump wear can sometimes be determined
by the use of _____ gauges. A slightly worn pump can
be _____.
15. Fasteners such as _____ or _____ are used to hold the
center support to the case.
16. Check the torque converter endplay with a _____
indicator.
Match the transmission component with the measuring
device used to check it.
17. Clutch pack clearance _____
18. Band servo operation _____
19. Shaft straightness _____
20. Shaft bushings _____
21. Overheated steel plates _____
22. Thrust washer thickness _____
(A) Dial indicator
and V-blocks
(B) Micrometer
(C) Air pressure
(D) Vacuum pump
and gauge
(E) Feeler gauge
(F) Visual inspection
(G) Inserting and
rocking the shaft