Dodge 2001 Ram 1500 Owner's Manual page 2296

BR/BE
AUTOMATIC TRANSMISSION - 47RE (Continued)
PRESSURE TEST ANALYSIS CHART
TEST CONDITION
Line pressure OK during
any one test
Line pressure OK in R
but low in D, 2, 1
Pressure low in D Fourth
Gear Range
Pressure OK in 1, 2 but
low in D3 and R
Pressure OK in 2 but low
in R and 1
Front servo pressure in 2
Pressure low in all
positions
Governor pressure too
high at idle speed
Governor pressure low at
all mph figures
Lubrication pressure low
at all throttle positions
Line pressure high
Line pressure low
DIAGNOSIS AND TESTING - AIR TESTING
TRANSMISSION CLUTCH AND BAND
OPERATION
Air-pressure testing can be used to check transmis-
sion front/rear clutch and band operation. The test
can be conducted with the transmission either in the
vehicle or on the work bench, as a final check, after
overhaul.
Air-pressure testing requires that the oil pan and
valve body be removed from the transmission. The
servo and clutch apply passages are shown (Fig. 10).
INDICATION
Pump and regulator
valve OK
Leakage in rear clutch
area (seal rings, clutch
seals)
Overdrive clutch piston
seal, or check ball
problem
Leakage in front clutch
area
Leakage in rear servo
Leakage in servo; broken
servo ring or cracked
servo piston
Clogged filter, stuck
regulator valve, worn or
faulty pump, low oil level
Governor pressure
solenoid valve system
fault. Refer to diagnostic
book.
Faulty governor pressure
solenoid, transmission
control module, or
governor pressure
sensor
Clogged fluid cooler or
lines, seal rings leaking,
worn pump bushings,
pump, clutch retainer, or
clogged filter.
Output shaft plugged,
sticky regulator valve
Sticky regulator valve,
clogged filter, worn pump
AUTOMATIC TRANSMISSION - 47RE
Fig. 10 Air Pressure Test Passages
1 - LINE PRESSURE TO ACCUMULATOR
2 - REAR SERVO APPLY
3 - FRONT SERVO APPLY
4 - FRONT SERVO RELEASE
5 - PUMP SUCTION
6 - PUMP PRESSURE
7 - FRONT CLUTCH APPLY
8 - REAR CLUTCH APPLY
9 - TO TORQUE CONVERTOR
10 - TO COOLER
11 - FROM TORQUE CONVERTER
Front Clutch Air Test
Place one or two fingers on the clutch housing and
apply air pressure through front clutch apply pas-
sage. Piston movement can be felt and a soft thump
heard as the clutch applies.
Rear Clutch Air Test
Place one or two fingers on the clutch housing and
apply air pressure through rear clutch apply passage.
Piston movement can be felt and a soft thump heard
as the clutch applies.
Front Servo Air Test
Apply air pressure to the front servo apply pas-
sage. The servo rod should extend and cause the
band to tighten around the drum. Spring pressure
should release the servo when air pressure is
removed.
Rear Servo Air Test
Apply air pressure to the rear servo apply passage.
The servo rod should extend and cause the band to
tighten around the drum. Spring pressure should
release the servo when air pressure is removed.
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