Remove the front oil pump seal as shown in
Figure 17-6. It is generally easier to remove the seal before
the oil pump is removed because the extra weight of the
transmission/transaxle assembly allows you to use the slide
hammer more efficiently. The front pump seal should
always be changed when the pump is serviced.
The oil pump can be removed next. Manufacturers
sometimes recommend removing the input shaft before
removing the oil pump. However, some transmissions and
transaxles are constructed so that the input shaft is pressed
into the front clutch drum. In these designs, the shaft
cannot be removed before the pump.
The pump usually fits tightly in the case, and some
pressure must be applied to remove it. Some pumps can be
removed by prying them out with a screwdriver or pry bar
(once the valve body has been removed). Others must be
removed with slide hammers or special pullers, Figure 17-7.
When removing the oil pump, always look for thrust
washers, which may fall out of place. A few oil pumps
have a clutch apply piston installed in their inner face. When
this is the case, a set of friction discs and clutch plates is
installed directly behind the pump. These parts should be
removed and placed with the pump for later service.
Removing Internal Components
With all the external parts out of the way, the internal
components, such as the input shaft, bands, clutch packs,
planetary gearsets, and output shaft, can be removed.
Removal steps are similar for all manufacturers. The major
factor affecting disassembly is whether or not the transmis-
sion or transaxle uses a center support.
On units without center supports, removing internal
components is usually a simple matter once the oil front
pump is removed. A typical procedure might involve loos-
ening the front band adjuster, sliding the band out of the
case, and then removing the forward clutch packs, front
planetary gearset, and input shell as an assembly. Be sure to
save all thrust washers, as they come out with these parts.
Once the front components have been removed, the
rear planetary gearsets and holding members, as well as
the output shaft, can be removed. Rear gearsets are
removed through the front of the case. The output shaft
will usually come out through the rear of the case.
Note that some clutch packs are held in place by a
snap ring located on the sun gear, inside the input shell.
This snap ring must be removed before the clutch pack and
other internal parts can be removed. In addition, some rear
planetary gearsets are held in place by a snap ring on the
front of the output shaft. This snap ring must be removed
in order to completely disassemble these components.
Make sure the shaft does not fall out of the case after the
snap ring is removed. Also, do not distort or stretch snap
rings when removing them. Use snap ring pliers or another
suitable tool.
As mentioned, some automatic transmissions have a
center support. The center support in an automatic trans-
mission may be retained by one or two case bolts located
under the valve body and, sometimes, by bolts on the
outside of the case. Other center supports are held in place
by a retaining ring in the case, Figure 17-8. The center
support keeps the rear clutches and gearsets in place.
Always make sure the center support bolts or retaining
rings have been removed before attempting to remove the
center support and mechanical components.
Once the center support has been removed, the rear
planetary gearsets, bands, clutches, and output shaft can
404 Automatic Transmissions and Transaxles
Remove old
front pump
seal
Seal remover
adapter
Slide
hammer
Figure 17-6. It is easier to remove the front pump seal with the
transmission or transaxle assembled. The weight of the unit
allows the slide hammer to exert more force on the seal. (Ford)
Oil pump
Pullers
Figure 17-7. Some pumps can be removed by pushing them
out from the rear. On many transmissions and transaxles, how-
ever, the pump cannot be reached from the rear and must be
removed with a slide hammer or special puller. (Ford)
Caution: Attempting to drive the rear
clutch, planetary gearset, and shaft assem-
blies from the case without first removing
the center support fasteners will severely damage
these components, the center support, and the case.