Jeep cherokee 1989, Owner'S Manual

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7B-2
Chapter 7 Part B Automatic transmission
maintenance, adjustment and removal and installation procedures.
If the transmission requires major repair work, it should be left t o
a dealer service department or an automotive or transmission repair
shop. You can, however, remove and install the transmission yourself
and save the expense, even if the repair work is done by a transmission
shop.
2
Diagnosis
-
general
Note: Automatic transmission malfunctions may be caused b y five
general conditions: poor engine performance, improper adjustments,
hydraulic malfunctions, mechanical malfunctions or malfunctions i n
the computer or its signal network. Diagnosis o f these problems should
always begin with a check o f the easily repaired items: fluid level and
condition (Chapter shift linkage adjustment and throttle linkage ad-
justment. Next, perform a road test to determine i f the problem has
been corrected or if more diagnosis i s necessary.
If
the problem persists
after the preliminary tests a n d corrections are completed, additional
diagnosis should be done b y a dealer service department or transmission
repair shop. Refer to the Troubleshooting Section at the front o f this
manual for information on symptoms o f transmission problems.
Preliminary checks
1 Drive the vehicle t o warm the transmission t o normal operating
temperature.
2 Check the fluid level as described in Chapter 1:
a) If the fluid level is unusually low, add enough fluid t o bring the
level within the designated area of the dipstick, then check for
external leaks (see below).
If the fluid level is abnormally high, drain off the excess, then
check the drained fluid for contamination by coolant. The
presence of engine coolant in the automatic transmission fluid
indicates that a failure has occurred in the internal radiator walls
that separate the coolant from the transmission fluid (see Chapter
If the fluid is foaming, drain it and refill the transmission, then
check for coolant in the fluid or a high fluid level.
3 Check the engine idle speed. Note: the engine i s malfunctioning,
do n o t proceed with the preliminary checks until
it
has been repaired
a n d runs normally.
4 Check the throttle valve linkage for freedom of movement. Adjust
it
if necessary (Section Note: The throttle valve linkage may function
properly when the engine is shut o f f and cold, b u t
i t
may malfunction
once the engine i s hot. Check
it
cold and a t normal engine operating
temperature.
5
Inspect the shift control linkage (see Section Make sure it's
properly adjusted and the linkage operates smoothly.
Fluid leak diagnosis
6 Most fluid leaks are easy t o locate visually. Repair usually consists
of replacing a seal or gasket. If a leak is difficult t o find, the following
procedure may help.
7
Identify the fluid. Make sure it's transmission fluid and not engine
oil or brake fluid (automatic transmission fluid is a deep red color).
8
Try t o pinpoint the source of the leak. Drive the vehicle several
miles, then park it over a large sheet of cardboard. After a minute or
two, you should be able t o locate the leak by determining the source
of the fluid dripping onto the cardboard.
9 Make a careful visual inspection of the suspected component and
the area immediately around it. Pay particular attention to gasket mating
surfaces.
A mirror is often helpful for finding leaks in areas that are
hard t o see.
1 0 If the leak still cannot be found, clean the suspected area thoroughly
with a degreaser or solvent, then dry it.
11 Drive the vehicle several miles at normal operating temperature
and varying speeds. After driving the vehicle, visually inspect the
suspected component again.
1 2 Once the leak has been located, the cause must be determined
before
it can be properly repaired. If a gasket is replaced but the sealing
flange is bent, the new gasket will not stop the leak. The bent flange
must be straightened.
13 Before attempting to repair a leak, check t o make sure the following
conditions are corrected or they may cause another leak. Note: Some
o f the following conditions cannot be fixed without highly specialized
tools a n d expertise. Such problems must be referred to a transmission
repair shop or a dealer service department.
Gasket leaks
1 4 Check the pan periodically. Make sure the bolts are tight, no bolts
are missing, the gasket is in good condition and the pan is flat (dents
in the pan may indicate damage t o the valve body inside).
1 5 If the pan gasket is leaking, the fluid level or the fluid pressure may
be too high, the vent may be plugged, the pan bolts may be too tight,
the pan sealing flange may be warped, the sealing surface of the trans-
mission housing may be damaged, the gasket may be damaged or the
transmission casting may be cracked or porous. If sealant instead of
gasket material has been used t o form a seal between the pan and the
transmission housing, it may be the wrong sealant.
Seal leaks
1 6 If a transmission seal is leaking, the fluid level or pressure may
be too high, the vent may be plugged, the seal bore may be damaged,
the seal itself may be damaged or improperly installed, the surface of
the shaft protruding through the seal may be damaged or a loose bearing
may be causing excessive shaft movement.
1 7 Make sure the dipstick tube seal is in good condition and the tube
is properly seated. Periodically check the area around the speedometer
gear or sensor for leakage. If transmission fluid is evident, check the
O-ring for damage.
Case leaks
1 8 If the case itself appears t o be leaking, the casting is porous and
will have t o be repaired or replaced.
1 9 Make sure the oil cooler hose fittings are tight and in good
condition.
Fluid comes out the vent pipe or fill tube
2 0 If this condition occurs, the transmission is overfilled, there is
coolant in the fluid, the case is porous, the dipstick is incorrect, the
vent is plugged or the drain back holes are plugged.
3 Shift linkage
-
check and adjustment
Refer to illustrations 3.3 and 3.4
Check
1
Firmly apply the parking brake and try t o momentarily operate the
starter in each shift lever position. The starter should operate in Park
and Neutral only. If the starter operates in any position other than Park
or Neutral, adjust the shift linkage (see below). If, after adjustment,
the starter still operates in positions other than Park or Neutral, the
neutral start switch is defective or in need of adjustment (see Section
Adjustment
2 Place the shift lever in Park. Raise the vehicle and support it securely
on jackstands.
3
On three-speed transmissions, loosen the shift rod jam nut, remove
the and disengage the trunnion and shift rod at the bellcrank
illustration).
4 On four-speed transmissions, release the adjuster clamp to unlock
the shift cable, then unsnap the shift cable from the cable bracket (see
illustration).
5 Be sure the shift lever on the transmission is all the way t o the
rear, in the last detent. This is the Park position.
6 Make sure the park lock is engaged by trying t o rotate the
driveshaft. The driveshaft will not rotate if the park lock is functioning
properly.
7
On transmissions, slide the shift rod trunnion forward
or backward the shift rod slot, as necessary, so the pin fits freely
in the bellcrank arm. Tighten the jam nut securely while holding the
shift rod so it doesn't turn as the jam nut is tightened. When properly
adjusted, there should be no lash in the shift linkage. Pull down on
the shift rod while pushing up on the outer part of the bellcrank t o
eliminate lash.
8
On four-speed transmissions, snap the shift cable into the bracket.
then press down on the adjuster clamp until it snaps in place t o lock
the shift cable.
9 Lower the vehicle.
1 0 With the parking brake firmly applied, make sure the engine starts
only in Park and Neutral. If the linkage appears t o be adjusted properly,
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