Jeep Grand Cherokee WJ. Manual - part 898
ACCUMULATOR
DESCRIPTION
The accumulator (Fig. 67) is a hydraulic device
that has the sole purpose of cushioning the applica-
tion of a band or clutch. The accumulator consists of
a dual-land piston and a spring located in a bore in
the transmission case. The 3-4 accumulator is located
in a housing attached to the side of the valve body
(Fig. 68).
OPERATION
Both the accumulator and the 3-4 accumulator
function the same. Line pressure is directed to the
small end of the piston when the transmission is
placed into a DRIVE position (Fig. 69), bottoming it
against the accumulator plate. When the 1-2 upshift
occurs (Fig. 70), line pressure is directed to the large
end of the piston and then to the kickdown servo. As
the line pressure reaches the accumulator, the com-
bination of spring pressure and line pressure forces
the piston away from the accumulator plate. This
causes a balanced pressure situation, which results
in a cushioned band application. After the kickdown
servo has become immovable, line pressure will fin-
ish pushing the accumulator up into its bore. When
the large end of the accumulator piston is seated in
its bore, the band or clutch is fully applied.
NOTE: The accumulator is shown in the inverted
position for illustrative purposes.
INSPECTION
Inspect the accumulator piston and seal rings (Fig.
71). Replace the seal rings if worn or cut. Replace the
piston if chipped or cracked.
Check condition of the accumulator inner and
outer springs (Fig. 71). Replace the springs if the
coils are cracked, distorted or collapsed.
Fig. 67 Accumulator
1 - ACCUMULATOR PISTON
2 - PISTON SPRING
Fig. 68 3-4 Accumulator and Housing
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
Fig. 69 Accumulator in DRIVE - FIRST Gear Position
1 - LINE PRESSURE
WG
AUTOMATIC - 44RE
21s - 99
2001 JEEP GRAND CHEROKEE