Dodge 2001 Ram 1500 Owner's Manual page 1782

BR/BE
AUTOMATIC TRANSMISSION - 42RE (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
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 - 42RE
DIAGNOSIS AND TESTING - AIR CHECKING
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).
Fig. 10 Air Pressure Test Passages
1 - REAR SERVO APPLY
2 - FRONT SERVO APPLY
3 - PUMP SUCTION
4 - FRONT CLUTCH APPLY
5 - FRONT SERVO RELEASE
6 - LINE PRESSURE TO ACCUMULATOR
7 - PUMP PRESSURE
8 - TO CONVERTER
9 - REAR CLUTCH APPLY
10 - FROM CONVERTER
11 - TO COOLER
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.
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