3. Lower vehicle.
4. Turn OD switch on.
5. Secure test gauge so it can be viewed from drivers 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 524-565 kPa (76-82 psi) with closed throttle and increase to 690-896 kPa (100-130 psi) at
1/2to3/4throttle.Notethatpressurecanincreasetoaround965kPa(140psi) at full throttle.
9. Return to shop or move vehicle off chassis dyno.
PRESSURE TEST ANALYSIS CHART
TEST CONDITION INDICATION
Line pressure OK during any one test Pump and regulator valve OK
Line pressure OK in R but low in D, 2, 1 Leakage in rear clutch area (seal rings, clutch seals)
Pressure low in D Fourth Gear Range Overdrive clutch piston seal, or check ball problem
Pressure OK in 1, 2 but low in D3 and R Leakage in front clutch area
Pressure OK in 2 but low in R and 1 Leakage in rear servo
Front servo pressure in 2 Leakage in servo; broken servo ring or cracked servo
piston
Pressure low in all positions Clogged filter, stuck regulator valve, wornor faulty
pump, low oil level
Governor pressure too high at idle speed Governor pressure solenoid valvesystem fault. Refer
to diagnostic book.
Governor pressure low at all mph figures Faulty governor pressure solenoid, transmission
control module, or governor pressure sensor
Lubrication pressure low at all throttle positions Clogged fluid cooler or lines, seal rings leaking, worn
pump bushings, pump, clutch retainer, or clogged filter.
Line pressure high Output shaft plugged, sticky regulator valve
Line pressure low Sticky regulator valve, clogged filter, worn pump
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 vehi-
cle or on the work bench, as a final check, after over-
haul.
Air-pressure testing requires that the oil pan and valve
body be removed from the transmission. The servo
and clutch apply passages are shown.
Front Clutch Air Test
Place one or two fingers on the clutch housing and apply air pressure through front clutch apply passage. 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 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.
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.
CONVERTER HOUSING FLUID LEAK
When diagnosing converter housing fluid leaks, two
items must be established before repair.
1. Verify that a leak condition actually exists.
2. Determined the true source of the leak.
Some suspected converter housing fluid leaks may
not be leaks at all. They may only be the result of
residual fluid in the converter housing, or excess fluid
spilled during factory fill or fill after repair. Converter
housing leaks have several potential sources. Through
careful observation, a leak source can be identified
before removing the transmission for repair. Pump
seal leaks tend to move along the drive hub and onto
the rear of the converter. Pump body leaks follow the
same path as a seal leak. Pump vent or pump attach-
ing bolt leaks are generally deposited on the inside of
the converter housing and not on the converter itself.
Pump o-ring or gasket leaks usually travel down the
inside of the converter housing. Front band lever pin
plug leaks are generally deposited on the housing and
not on the converter.
TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are:
Leaks at the weld joint around the outside diameter weld.
Leaks at the converter hub weld.
CONVERTER HOUSING AREA LEAK CORRECTION
1. Remove converter.
2. Tighten front band adjusting screw until band is tight around front clutch retainer. This prevents front/rear clutches
from coming out when oil pump is removed.
3. Remove oil pump and remove pump seal. Inspect pump housing drainback andvent holes for obstructions. Clear
holes with solvent and wire.
4. Inspect pump bushing and converter hub. If bushing is scored, replace it. If converter hub is scored, either polish
it with crocus cloth or replace converter.
1 - PUMP SEAL
2-PUMPVENT
3-PUMPBOLT
4 - PUMP GASKET
5 - CONVERTER HOUSING
6 - CONVERTER
7 - REAR MAIN SEAL LEAK
5. Install new pump seal, O-ring, and gasket. Replace oil pump if cracked, porous or damaged in any way. Be sure
to loosen the front band before installing the oil pump, damage to the oil pump seal may occur if the band is still
tightened to the frontclutch retainer.
6. Loosen kickdown lever pin access plug three turns. Apply Loctite™ 592, orPermatex
No. 2 to plug threads and
tightenplugto17Nꞏm(150in.lbs.)torque.
7. Adjust front band.
8. Lubricate pump seal and converter hub with transmission fluid or petroleum jelly and install converter.
9. Install transmission and converter housing dust shield.
10. Lower vehicle.
DIAGNOSIS CHARTS
The diagnosis charts provide additional reference when diagnosing a transmission fault. The charts provide general
information on a variety of transmission, overdrive unit and converter clutch fault conditions.
The hydraulic flow charts in the Schematics and Diagrams section of this group, outline fluid flow and hydraulic
circuitry. Circuit operation is provided for PARK, NEUTRAL, FIRST, SECOND, THIRD, FOURTH, MANUAL FIRST,
MANUAL SECOND, and REVERSE gear ranges. Normal working pressures are alsosupplied for each of the gear
ranges.
Diagnosis Charts
CONDITION POSSIBLE CAUSES CORRECTION
HARSH ENGAGEMENT
(FROM NEUTRAL TO
DRIVE OR REVERSE)1. Fluid Level Low. 1. Add Fluid
2. Throttle Linkage Mis-adjusted.
V- 1 0 O n l y2. Adjust linkage - setting may be too long.
3. Mount and Driveline Bolts Loose. 3. Check engine mount, transmission
mount, propeller shaft, rear spring to body
bolts, rear control arms, crossmember and
axle bolt torque. Tighten loose bolts and
replace missing bolts.
4. U-Joint Worn/Broken. 4. Remove propeller shaft and replace
U-Joint.
5. Axle Backlash Incorrect. 5. Check per Service Manual. Correct as
needed.
6. Hydraulic Pressure Incorrect. 6. Check pressure. Remove, overhaul or
adjust valve body as needed.
7. Band Mis-adjusted. 7. Adjust rear band.
8. Valve Body Check Balls Missing. 8. Inspect valve body for proper check ball
installation.
9. Axle Pinion Flange Loose. 9. Replace nut and check pinion threads
before installing new nut. Replace pinion
gear if threads are damaged.
10. Clutch, band or planetary
component damaged.10. Remove, disassemble and repair
transmission as necessary.
11. Converter Clutch Faulty. 11. Replace converter and flush cooler and
line before installing new converter.
CONDITION POSSIBLE CAUSES CORRECTION
DELAYED ENGAGEMENT
(FROM NEUTRAL TO
DRIVE OR REVERSE)1. Fluid Level Low. 1. Correct level and check for leaks.
2. Filter Clogged. 2. Change filter.
3. Gearshift Linkage Mis-adjusted. 3. Adjust linkage and repair linkage ifworn
or damaged.
4. Torque Converter Drain Back (Oil
drains from torque converter into
transmission sump).4. If vehicle moves normally after 5
seconds after shifting into gear, no repair is
necessary. If longer, inspect pump bushing
for wear. Replace pump house.
5. Rear Band Mis-adjusted. 5. Adjust band.
6. Valve Body Filter Plugged. 6. Replace fluid and filter. If oil pan and old
fluid were full of clutch disc material and/or
metal particles, overhaul will be necessary.
7. Oil Pump Gears Worn/Damaged. 7. Remove transmission and replace oil
pump.
8. Governor Circuit and Solenoid
Valve Electrical Fault.8. Test with DRB
scan tool and repair as
required.
9. Hydraulic Pressure Incorrect. 9. Perform pressure test, remove
transmission and repair as needed.
10. Reaction Shaft Seal Rings
Worn/Broken.10. Remove transmission, remove oil pump
and replace seal rings.
11. Rear Clutch/Input Shaft, Rear
Clutch Seal Rings Damaged.11. Remove and disassemble transmission
and repair as necessary.
12. Regulator Valve Stuck. 12. Clean.
13. Cooler Plugged. 13. Transfer case failure can plug cooler.
NO DRIVE RANGE
(REVERSE OK)1. Fluid Level Low. 1. Add fluid and check for leaks if drive is
restored.
2. Gearshift Linkage/Cable
Loose/Misadjusted.2. Repair or replace linkage components.
3. Rear Clutch Burnt. 3. Removeand disassemble transmission
and rear clutch and seals. Repair/replace
worn or damaged parts as needed.
4. Valve Body Malfunction. 4. Remove and disassemble valve body.
Replace assembly if any valves or bores
are damaged.
5. Transmission Overrunning Clutch
Broken.5. Remove and disassemble transmission.
Replace overrunning clutch.
6. Input Shaft Seal Rings Worn/
Damaged.6. Remove and disassemble transmission.
Replace seal rings and any other worn or
damaged parts.
7. Front Planetary Failed Broken. 7. Remove and repair.
CONDITION POSSIBLE CAUSES CORRECTION
NO DRIVE OR REVERSE
(VEHICLE WILL NOT
MOVE)1. Fluid Level Low. 1. Add fluid and check for leaks if drive is
restored.
2. Gearshift Linkage/Cable
Loose/Misadjusted.2. Inspect, adjust and reassemble linkage
as needed. Replace worn/damaged parts.
3. U-Joint/Axle/Transfer Case
Broken.3. Perform preliminary inspection procedure
for vehicle that will not move. Refer to
procedure in diagnosis section.
4. Filter Plugged. 4. Remove and disassemble transmission.
Repair or replace failed components as
needed. Replace filter. If filter and fluid
contained clutch material or metal particles,
an overhaul may be necessary. Perform
lube flow test. Flush oil. Replace cooler as
necessary.
5. Oil Pump Damaged. 5. Perform pressure test to confirm low
pressure. Replace pump body assembly if
necessary.
6. Valve Body Malfunctioned. 6. Check and inspect valve body. Replace
valve body (as assembly) if any valve or
bore is damaged. Clean and reassemble
correctly if all parts are in good condition.
7. Transmission Internal Component
Damaged.7. Remove and disassemble transmission.
Repair or replace failed components as
needed.
8. Park Sprag not Releasing - Check
Stall Speed, Worn/Damaged/Stuck.8. Remove, disassemble, repair.
9. Torque Converter Damage. 9. Inspect and replace as required.
SHIFTS DELAYED OR
ERRATIC (SHIFTS ALSO
HARSH AT TIMES)1. Fluid Level Low/High. 1. Correct fluid level and check for leaks if
low.
2. Fluid Filter Clogged. 2. Replace filter. If filter and fluid contained
clutch material or metal particles, an
overhaul may be necessary. Perform lube
flow test.
3. Throttle Linkage Mis-adjusted.
V- 1 0 O n l y3. Adjust linkage as described in service
section.
4. Throttle Linkage Binding. V-10
Only4. Check cable for binding. Check for return
to closed throttle at transmission.
5. Gearshift Linkage/Cable
Mis-adjusted.5. Adjust linkage/cable as described in
service section.
6. Clutch or Servo Failure. 6. Remove valve body and air test clutch,
and band servo operation. Disassemble
and repair transmission as needed.
7. Governor Circuit Electrical Fault. 7. Test using DRB
scan tool and repair as
required.
8. Front Band Mis-adjusted. 8. Adjust band.
9. Pump Suction Passage Leak. 9. Check for excessive foam on dipstick
after normal driving. Check for loose pump
bolts, defective gasket. Replace pump
assembly if needed.
CONDITION POSSIBLE CAUSES CORRECTION
SLIPS IN REVERSE ONLY 1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Gearshift Linkage Mis-adjusted. 2. Adjust linkage.
3. Rear Band Mis-adjusted. 3. Adjust band.
4. Rear Band Worn. 4. Replace as required.
5. Overdrive Direct Clutch Worn. 5. Disassemble overdrive. Repair as
needed.
6. Hydraulic Pressure Too Low. 6. Perform hydraulic pressure tests to
determine cause.
7. Rear Servo Leaking. 7. Air pressure check clutch-servo operation
and repair as required.
8. Band Linkage Binding. 8. Inspect and repair as required.
SLIPS IN FORWARD
DRIVE RANGES1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Fluid Foaming. 2. Check for high oil level, bad pump
gasket or seals, dirt between pump halves
and loose pump bolts. Replace pump if
necessary.
3. Throttle Linkage Mis-adjusted.
V- 1 0 O n l y3. Adjust linkage.
4. Gearshift Linkage Mis-adjusted. 4. Adjust linkage.
5. Rear Clutch Worn. 5. Inspect and replace as needed.
6. Low Hydraulic Pressure Due to
Worn Pump, Incorrect Control
Pressure Adjustments, Valve Body
Warpage or Malfunction, Sticking,
Leaking Seal Rings, Clutch Seals
Leaking, Servo Leaks, Clogged Filter
or Cooler Lines.6. Perform hydraulic and air pressure tests
to determine cause.
7. Rear Clutch Malfunction, Leaking
Seals or Worn Plates.7. Air pressure check clutch-servo operation
and repair as required.
8. Overrunning Clutch Worn, Not
Holding (Slips in 1 Only).8. Replace Clutch.
SLIPS IN LOW GEAR
D
ONLY, BUT NOT IN
MANUAL 1 POSITIONOverrunning Clutch Faulty. Replace overrunning clutch.
GROWLING, GRATING OR
SCRAPING NOISES1. Drive Plate Broken. 1. Replace.
2. Torque Converter Bolts Hitting
Dust Shield.2. Dust shield bent. Replace or repair.
3. Planetary Gear Set Broken/
Seized.3. Check for debris in oil pan and repair as
required.
4. Overrunning Clutch Worn/Broken. 4. Inspect and check for debris in oil pan.
Repair as required.
5. Oil Pump Components Scored/
Binding.5. Remove, inspect and repair as required.
6. Output Shaft Bearing or Bushing
Damaged.6. Remove, inspect and repair as required.
7. Clutch Operation Faulty. 7. Perform air pressure check and repair as
required.
8. Front and Rear Bands Mis-
adjusted.8. Adjust bands.
CONDITION POSSIBLE CAUSES CORRECTION
DRAGS OR LOCKS UP 1. Fluid Level Low. 1. Check and adjust level.
2. Clutch Dragging/Failed 2. Air pressure check clutch operation and
repair as required.
3. Front or Rear Band Mis-adjusted. 3. Adjust bands.
4. Case Leaks Internally. 4. Check for leakage between passages in
case.
5. Servo Band or Linkage
Malfunction.5. Air pressure check servo operation and
repair as required.
6. Overrunning Clutch Worn. 6. Remove and inspect clutch. Repair as
required.
7. Planetary Gears Broken. 7. Remove, inspect and repair as required
(look for debris in oil pan).
8. Converter Clutch Dragging. 8. Check for plugged cooler. Perform flow
check. Inspect pump for excessive side
clearance. Replace pump as required.
NO 4-3 DOWNSHIFT 1. Circuit Wiring and/or Connectors
Shorted.1. Test wiring and connectors with test lamp
and volt/ohmmeter. Repair wiring as
necessary. Replace connectors and/or
harnesses as required.
2. PCM Malfunction. 2. Check PCM operation with DRB
scan
tool. Replace PCM only if faulty.
3. TPS Malfunction 3. Check TPS with DRB
scan tool at PCM.
4. Lockup Solenoid Not Venting. 4. Remove valve body and replace solenoid
assembly if plugged or shorted.
5. Overdrive Solenoid Not Venting. 5. Remove valve body and replace solenoid
if plugged or shorted.
6. Valve Body Valve Sticking. 6. Repair stuck 3-4 shift valve or lockup
timing valve.
NO 4-3 DOWNSHIFT
WHEN CONTROL SWITCH
IS TURNED OFF1. Control Switch Open/Shorted. 1. Test and replace switch if faulty.
2. Overdrive Solenoid Connector
Shorted.2. Test solenoids and replace if seized or
shorted.
3. PCM Malfunction. 3. Test with DRB
scan tool. Replace PCM
if faulty.
4. Valve Body Stuck Valves. 4. Repair stuck 3-4, lockup or lockup timing
valve.
CLUNK NOISE FROM
DRIVELINE ON CLOSED
THROTTLE 4-3
DOWNSHIFT1. Transmission Fluid Low. 1. Add Fluid.
2. Throttle Cable Mis-adjusted. V-10
Only2. Adjust cable.
3. Overdrive Clutch Select Spacer
Wrong Spacer.3. Replace overdrive piston thrust plate
spacer.
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS. 1. Fluid Lines and Fittings Loose/
Leaks/Damaged.1. Tighten fittings. If leaks persist, replace
fittings and lines if necessary.
2. Fill Tube (where tube enters case)
Leaks/Damaged.2. Replace tube seal. Inspect tube for
cracks in fill tube.
3. Pressure Port Plug Loose
Loose/Damaged.3. Tighten to correct torque. Replace plug
or reseal if leak persists.
4. Pan Gasket Leaks. 4. Tighten pan screws (150 in. lbs.). If leaks
persist, replace gasket.
5. Valve Body Manual Lever Shaft
Seal Leaks/Worn.5. Replace shaft seal.
6. Rear Bearing Access Plate Leaks. 6. Replace gasket. Tighten screws.
7. Gasket Damaged or Bolts are
Loose.7. Replace bolts or gasket or tighten both.
8. Adapter/Extension Gasket
Damaged Leaks/Damaged.8. Replace gasket.
9. Park/Neutral Switch, or
Transmission Range Sensor
Leaks/Damaged.9. Replace switch and gasket.
10. Converter Housing Area Leaks. 10. Check for leaks at seal caused by worn
seal or burr on converter hub (cutting seal),
worn bushing, missing oil return, oil in front
pump housing or hole plugged. Check for
leaks past O-ring seal on pump or past
pump-to-case bolts; pump housing porous,
oil coming out vent due to overfill or leak
past front band shaft access plug.
11. Pump Seal Leaks/Worn/
Damaged.11. Replace seal.
12. Torque Converter Weld
Leak/Cracked Hub.12. Replace converter.
13. Case Porosity Leaks. 13. Replace case.
NOISY OPERATION IN
FOURTH GEAR ONLY1. Overdrive Clutch Discs, Plates or
Snap Rings Damaged.1. Remove unit and rebuild clutch pack.
2. Overdrive Piston or Planetary
Thrust Bearing Damaged.2. Remove and disassemble unit. Replace
either thrust bearing if damaged.
3. Output Shaft Bearings Scored/
Damaged.3. Remove and disassemble unit. Replace
either bearing if damaged.
4. Planetary Gears Worn/Chipped. 4. Remove and overhaul overdrive unit.
5. Overdrive Unit Overrunning Clutch
Rollers Worn/Scored.5. Remove and overhaul overdrive unit.
STANDARD PROCEDURE - ALUMINUM THREAD REPAIR
DamagedorwornthreadsinthealuminumtransmissioncaseandvalvebodycanberepairedbytheuseofHeli-
Coils™, or equivalent. This repair consists of drilling out the worn-out damaged threads. Then tap the hole with a
special Heli-Coil™ tap, or equivalent, and installing a Heli-Coil™ insert, or equivalent, into the hole. This brings the
hole back to its original thread size.
Heli-Coil™, or equivalent, tools and inserts are readily available from most automotive parts suppliers.