Chrysler 1991 Service Manual Supplement page 131

21 • 2 TRANSMISSION
•
FLUID TEMPERATURE THERMO-SWITCHES
Fourth gear operation in the diesel A518 is also
controlled by two temperature sensitive thermo-
switchos. . .. •
The first thermo-switch is the engine coolant tem-
perature switch. This switch prevents overdrive
fourth gear operation when engine coolant tempera-
ture is below approximately 65° F.
The second thermo-switch directly monitors trans-
mission fluid temperature. The switch ' will either
downshift the transmission to third gear, or prevent
a 3-4 upshift when fluid temperature exceeds
270-275° F.
The f|uid temperature switch is located in a boss
built intp the cooler outlet line. The boss and switch
are located approximately 2-3 inches from the outlet
line fitting in the transmission case.
The engine coolant and fluid temperature switches
are in circuit with the overdrive control switch in the
instrument panel. A detailed schematic showing
switch circuitry and connection is provided in Group
14 of-this supplement.
SERVICE PROCEDURE AND SPECIFICATION
CHANGES
Specifications and repair procedures for the diesel
and gas engine versions of the A518 are basically the
same. The only component requiring different service
methods is the new overrunning clutch.
Service procedures for the new overrunning clutch
are included in this supplement section. Refer to the
1991 shop manual for all other A518 service proce-
dures.
SERVICING THE NEW OVERRUNNING CLUTCH
CLUTCH COMPONENT REMOVAL
(1) Disassemble the transmission down to the low-
reverse drum as described in Group 21 of the 1991
manual.
(2) Remove the snap ring that retains the low-re-
verse drum on the overdrive piston retainer hub.
(3) Slide the low-reverse drum off the retainer hub
and out of the rear band (Fig. 1).
(4) Note that the overrunning clutch race will re-
main on the splines of the low-reverse drum after re-
moval (Fig. 2). The race is a permanent press fit
on the hub splines. Do not attempt to remove the
race.
(5) Remove the overrunning clutch assembly (Fig.
3). The assembly can be removed without displacing
the rollers and springs if care is exercised. Note po-
sition of the rollers and springs for assembly refer-
ence.
(6) Examine the clutch cam (Fig. 3). I f the cam is
worn, damaged, or loose, replace it. Refer to the pro-
cedure in the A518 section, Group 21 of the 1991
manual.
J9221-8
Fig. 2 Overrunning Ctutch Race Position
(7) Examine the overrunning clutch race. Replace
the low-reverse drum and race as an assembly if ei-
ther the race, or drum is worn or damaged. Also re-
place the entire assembly if the race is loose on the
splines of the drum hub.
CLUTCH COMPONENT INSTALLATION
(1) Lubricate the overdrive piston retainer hub,
clutch race, clutch cam, and overrunning clutch roll-
ers with Mopar ATF Plus, or Dexron II®.
(2) If any of the overrunning clutch rollers and
springs came out of the retainer, reinstall them as
follows: Install and seat the spring in the retainer
first. Then insert the roller between the spring and
retainer stop as shown (Fig. 4). Verify that each
roller and spring are fully seated before proceeding.