overheating JEEP CHEROKEE 1995 Service Owner's Manual

(4) Apply parking brakes.
(5) Shift transmission momentarily into all gear
ranges. Then shift transmission back to Neutral.
(6) Clean top of filler tube and dipstick to keep dirt
from entering tube.
(7) Remove dipstick and check fluid level as fol-
lows:
(a) Dipstick has three fluid level indicator levels
(Fig. 1) which are: a MIN dot, an OK crosshatch
area, and a MAX fill arrow.
(b) Correct maximum level is to MAX arrow
mark. Correct acceptable level is to OK mark in
crosshatch area.
(c) Incorrect level is at or below MIN dot.
(d) If fluid is low, add only enough Mopar ATF
Plus to restore correct level. Do not overfill.
CAUTION: Do not overfill the transmission. Overfill-
ing may cause leakage out the pump vent which
can be mistaken for a pump seal leak. Overfilling
will also cause fluid aeration and foaming as the ex-
cess fluid is picked up and churned by the gear
train. This will significantly reduce fluid life.
EFFECTS OF INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn
the fluid into foam. This aerates the fluid causing the
same conditions that occur with a low level.
In either case, air bubbles cause fluid overheating,
oxidation and varnish buildup which interferes with
valve, clutch and servo operation. Foaming also
causes fluid expansion which can result in fluid over-
flow from the transmission vent or fill tube. Fluid
overflow can easily be mistaken for a leak if inspec-
tion is not careful.
TRANSMISSION THROTTLE VALVE CABLE
ADJUSTMENT
Throttle cable adjustment is important to proper
operation. This adjustment positions the throttle
valve which controls shift speed, quality and part
throttle downshift sensitivity.
If cable adjustment setting is too short, early shifts
and slippage between shifts may occur. If the setting
is too long, shifts may be delayed and part throttle
downshifts may be very sensitive. Refer to the In-Ve-
hicle Service section for adjustment procedure.
GEARSHIFT CABLE/LINKAGE ADJUSTMENT
Gearshift cable/linkage adjustment is important be-
cause it positions the valve body manual valve. Incor-
rect adjustment will cause creeping in Neutral,
premature clutch wear, delayed engagement in any
gear, or a no-start in Park or Neutral position.Proper operation of the neutral start switch will
provide a quick check on adjustment. Refer to the In-
Vehicle Service section for adjustment procedure.
ROAD TEST
Before road testing, be sure the fluid level and all
cable/linkage adjustments have been checked and ad-
justed if necessary.
Observe engine performance during the road test. A
poorly tuned engine will not allow an accurate anal-
ysis of transmission operation.
Operate the transmission in all gear ranges. Check
for slippage and shift variations. Note whether the
shifts are harsh, spongy, delayed, early, or if part
throttle downshifts are sensitive.
Watch closely for slippage or engine flare which
usually indicates clutch, band or overrunning clutch
problems. If the condition is advanced, an overhaul
may be necessary to restore normal operation.
A slipping clutch or band can often be determined
by comparing which internal units are applied in the
various gear ranges. The Clutch and Band Applica-
tion chart (Fig. 3) provides a basis for analyzing road
test results.
ANALYZING THE ROAD TEST
Refer to the Clutch and Band Application chart
(Fig. 3) and note which elements are in use in the
various gear ranges.
The rear clutch is applied in all forward ranges (D,
2, 1). The overrunning clutch is applied in first gear
(D and 2 range only). The rear band is applied in 1
and R range only.
For example: If slippage occurs in first gear in D
and 2 range but not in 1 range, the overrunning
Fig. 3 Clutch And Band Application Chart
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 71

CONNECTING COOLER LINES AND FITTINGS
(ALL TYPES)
(1) Wipe cooler line and fitting clean with shop
towel.
(2) Insert cooler line into fitting. Then push line
inward until retainer or insert secures line. A snap or
click sound will be heard when the insert tabs or re-
tainer clip seats behind the cooler line flange.
(3)Pull outward on cooler lines/fittings to
verify they are properly secured.
CAUTION: The wire retainer clips or insert release
tabs secure the cooler lines. If the clips or tabs are
deformed, distorted, or not fully seated, normal
fluid pressure could unseat the lines resulting in
fluid loss and transmission damage. Be very sure
the cooler lines are firmly secured as described in
step (3).
CONVERTER DRAINBACK CHECK VALVE SERVICE
The converter drainback check valve is located in
the cooler outlet (pressure) line near the radiator
lower tank. The valve prevents fluid drainback when
the vehicle is parked for lengthy periods. The valve
check ball is spring loaded and has an opening pres-
sure of approximately 2 psi. Refer to the cooler flow
test procedure for valve testing.
The valve is serviced as an assembly; it is not re-
pairable. Do not clean the valve if restricted, or con-
taminated by sludge, or debris. If the valve fails, or if
a transmission malfunction occurs that generates
sludge and/or clutch particles and metal shavings,
the valve must be replaced.
The valve must be removed whenever the cooler
and lines are reverse flushed. The valve can be flow
tested when necessary. The procedure is exactly the
same as for flow testing a cooler.
If the valve is restricted, installed backwards, or in
the wrong line, it will cause an overheat condition
and possible transmission failure.
CAUTION: The drainback valve is a one-way valve.
As such, it must be properly oriented in terms of
flow direction. In addition, the valve must only beinstalled in the pressure line. Otherwise flow will be
blocked causing overheat and eventual transmis-
sion failure.
TRANSMISSION COOLER FLOW TESTING
The transmission main and auxiliary coolers, plus
the drainback valve, should be flow tested whenever
fluid overheating is noted.
Restricted flow caused by contamination, or a
cooler malfunction, reduces lubrication fluid flow
throughout the transmission. This can result in fluid
overheating, fluid breakdown, bushing wear, shift
problems and component failure.
Normal color of transmission fluid varies from
bright red, to light pink. Fluid overheating is indi-
cated when fluid color ranges from orange-brown to
black, and the fluid smells burned, or contains
sludge.
CAUTION: If a transmission malfunction contami-
nates the fluid with clutch disc and metal particles,
the cooler and lines must be reverse flushed thor-
oughly. Flushing will prevent sludge and particles
from flowing back into the transmission and con-
verter after repair.
Cooler flow is tested by measuring the amount of
fluid pumped through the cooler in a specified time
by the transmission oil pump.The same flow test
procedure is used for the drainback valve, main
cooler, and auxiliary cooler.
Cooler And Drainback Valve Flow Test Procedure
(1) Test flow throughdrainback valveas follows:
(a) Add extra quart of ATF Plus to transmission.
(b) Disconnect pressure line at radiator fitting, or
at drainback valve and position hose or valve end
in one quart test container.
(c) Shift transmission into neutral, run engine at
idle speed for 20 seconds, and note flow from valve.
Use stopwatch to check test time.
(d) Replace drainback valve if flow is less than
one quart in 20 seconds, is intermittent, or does
not flow at all.
(e) Connect pressure hose to radiator fitting and
proceed to cooler flow test.
(2) Test flow throughmain cooleras follows:
(a) Disconnect cooler return (rear) line at trans-
mission and place it in one quart test container.
(b) Add extra quart of fluid to transmission.
(c) Shift transmission into neutral, run engine at
idle speed for 20 seconds, and note flow from valve.
Use stopwatch to check test time.
(d) Replace cooler if fluid flow is less than one
quart in 20 seconds, is intermittent, or does not
flow at all.
Fig. 33 New Style Fitting Insert (On Cooler Line)
J30RH/32RH IN-VEHICLE SERVICE 21 - 113