Reverse Range; Move Throttle Lever All Way Forward Then All Way Rearward And Note Gauge Readings; Kpa) With Lever Forward And Increase To 230 - 280 Psi (1586-1931 Kpa) As Lever Is Moved Rearward; Test Five - Governor Pressure This Test Checks Governor Operation By Measuring - Dodge ram truck 3500 1996 Service Manual

21 - 114 AUTOMATIC TRANSMISSION—42RE B R
D I A G N O S I S
AND TESTING (Continued)
(5) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually
increase as lever is moved rearward.
(6) Front servo is pressurized only in D range and
should be same as line pressure within 3 psi (21 kPa)
up to downshift point.
Test Four - Transmission In Reverse
This test checks pump output, pressure regulation
and the front clutch and rear servo circuits. Use 300
psi Test Gauge C-3293-SP for this test.
(1) Connect 300 psi gauge to rear servo port (Fig.
9).
(2) Start and run engine at 1600 rpm for test.
(3) Move valve body selector lever four detents
rearward from the full forward position. This is
Reverse range.
(4) Move throttle lever all way forward then all
way rearward and note gauge readings.
(5) Pressure should be 145 - 175 psi (1000-1207
kPa) with lever forward and increase to 230 - 280 psi
(1586-1931 kPa) as lever is moved rearward.
Test Five - Governor Pressure
This test checks governor operation by measuring
governor pressure response to changes i n engine
speed. I t is usually not necessary to check governor
operation unless shift speeds are incorrect or i f the
transmission will not downshift.
(1) Connect 100 psi Test Gauge C-3292 to governor
pressure port (Fig. 9).
(2) Move shift lever to D range.
(3) Start and run engine at curb idle speed and
note pressure. At idle and with vehicle stopped, pres­
sure should be zero to 1.5 psi maximum. I f pressure
exceeds this figure, governor valve or weights are
sticking open.
(4) Slowly increase engine speed and observe
speedometer and pressure test gauge. Governor pres­
sure should increase in proportion to vehicle speed.
Or approximately 1 psi for every 1 mph.
(5) Pressure rise should be smooth and drop back
to 0 to 1.5 psi when wheels stop rotating.
(6) Compare results of pressure tests with analysis
charts (Fig. 10).
Test Six - Overdrive Fourth Gear
This test checks line pressure at the overdrive
clutch in fourth gear range. The test should be per­
formed on the road or on a chassis dynamometer. Do
not perform this test on a hoist. Use 300 psi Test
Gauge C-3292 for this test.
(1) Remove tachometer; i t is not needed for this
test.
(2) Move 300 psi Gauge to overdrive clutch pres­
sure test port. Then remove other gauge and reinstall
test port plug.
(3) Lower vehicle.
(4) Turn on OD switch.
(5) Secure test gauge so it can be viewed from
driver's seat.
(6) Start engine and shift into D range.
(7) Increase vehicle speed gradually until 3-4 shift
occurs and note gauge pressure.
(8) Pressure should be 469-496 kPa (68-72 psi)
with closed throttle and increase to 620-827 kPa (90-
120 psi) at 1/2 to 3/4 throttle. Note that pressure can
increase to around 896 kPa (130 psi) at full throttle.
(9) Return to shop or move vehicle off chassis
dynamometer.
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 low
in 2
Pressure low in all positions
Governor pressure too high
at idle speed, or governor
pressure low at all mph
Figures
Lubrication/line pressure
low at all throttle positions
I N D I C A T I O N
Pump and regulator valve OK
Leakage in rear clutch area (servo,
clutch seals, governor support
seal rings)
Overdrive clutch piston seal, or
check ball problem
Leakage in front clutch area (servo,
clutch seals, retainer bore, pump
seal rings)
Leakage in rear servo
Leakage in servo; broken servo
ring or cracked servo piston
Clogged filter, stuck regulator
valve, worn or faulty pump,
plugged fluid cooler
Faulty governor pressure solenoid,
transmission control module, or
governor pressure sensor
Clogged fluid cooler or lines, seal
rings leaking, output shaft plugged
witn debris, worn bushings in
pump or clutch retainer
J9521-168
Fig. 10 Pressure Test Analysis
C0NWERTER STALL TEST
Stall testing involves determining maximum
engine speed obtainable at full throttle with the rear
wheels locked and the transmission in D range. This
test checks the holding ability of the converter over­
running and transmission clutches. When stall test­
ing is completed, refer to the stall speed chart and
diagnosis guides.