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
neutral, third, fourth and reverse gear ranges. Normal
working pressures are also supplied for each of
the gear ranges.
CONDITION |
POSSIBLE CAUSES |
CORRECTION |
HARSH ENGAGEMENT
FROM NEUTRAL TO
DRIVE OR REVERSE |
- Fluid Level Low
- Throttle Linkage Misadjusted
- Mount and Driveline Bolts Loose
- U-Joint Worn/Broken
- Axle Backlash Incorrect
- Hydraulic Pressure Incorrect
- Band Misadjusted.
- Valve Body Check Balls Missing.
- Axle Pinion Flange Loose.
- Clutch, band or planetary
component Damaged.
- Converter Clutch (if equipped)
Faulty.
|
- Add Fluid
- Adjust linkage - setting may be too long.
- 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.
- Remove propeller shaft and replace
U-Joint.
- Check per Service Manual. Correct as
needed.
- Check pressure. Remove, overhaul or
adjust valve body as needed.
- Adjust rear band.
- Inspect valve body for proper check ball
installation.
- Replace nut and check pinion threads
before installing new nut. Replace pinion
gear if threads are damaged.
- Remove, disassemble and repair
transmission as necessary.
- Replace converter and flush cooler and
line before installing new converter.
|
DELAYED ENGAGEMENT
FROM NEUTRAL TO
DRIVE OR REVERSE |
- Fluid Level Low.
- Filter Clogged.
- Gearshift Linkage Misadjusted.
- Rear Band Misadjusted.
- Valve Body Filter Plugged.
- Oil Pump Gears Worn/Damaged.
- Hydraulic Pressure Incorrect.
- Reaction Shaft Seal Rings
Worn/Broken.
- Rear Clutch/Input Shaft, Rear
Clutch Seal Rings Damaged.
- Governor Valve Stuck.
- Regulator Valve Stuck.
- Cooler Plugged.
|
- Correct level and check for leaks.
- Change filter.
- Adjust linkage and repair linkage if worn
or damaged.
- Adjust band.
- Replace fluid and filter. If oil pan and old
fluid were full of clutch disc material and/or
metal particles, overhaul will be necessary.
- Remove transmission and replace oil
pump.
- Perform pressure test, remove
transmission and repair as needed.
- Remove transmission, remove oil pump
and replace seal rings.
- Remove and disassemble transmission
and repair as necessary.
- Remove and inspect governor
components. Replace worn or damaged
parts.
- Clean.
- Flush transmission cooler and inspect
convertor drainback valve.
|
NO DRIVE RANGE
(REVERSE OK) |
- Fluid Level Low.
- Gearshift Linkage/Cable
Loose/Misadjusted.
- Rear Clutch Burnt.
- Valve Body Malfunction.
- Transmission Overrunning Clutch
Broken.
- Input Shaft Seal Rings Worn/
Damaged.
- Front Planetary Failed Broken.
|
- Add fluid and check for leaks if drive is
restored.
- Repair or replace linkage components.
- Remove and disassemble transmission
and rear clutch and seals. Repair/replace
worn or damaged parts as needed.
- Remove and disassemble valve body.
Replace assembly if any valves or bores
are damaged.
- Remove and disassemble transmission.
Replace overrunning clutch.
- Remove and disassemble transmission.
Replace seal rings and any other worn or
damaged parts.
- Remove and repair.
|
NO DRIVE OR REVERSE
(VEHICLE WILL NOT
MOVE) |
- Fluid Level Low.
- Gearshift Linkage/Cable
Loose/Misadjusted.
- U-Joint/Axle/Transfer Case
Broken.
- Filter Plugged.
- Oil Pump Damaged.
- Valve Body Malfunctioned.
- Transmission Internal Component
Damaged.
- Park Sprag not Releasing
- Torque Converter Damage.
|
- Add fluid and check for leaks if drive is
restored.
- Inspect, adjust and reassemble linkage
as needed. Replace worn/damaged parts.
- Perform preliminary inspection procedure
for vehicle that will not move. Refer to
procedure in diagnosis section.
- 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.
- Perform pressure test to confirm low
pressure. Replace pump body assembly if
necessary.
- Check press 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.
- Remove and disassemble transmission.
Repair or replace failed components as
needed. Remove and disassemble
transmission. Repair or replace failed
components as needed.
- Remove, disassemble, repair.
- Check Stall Speed, Worn/Damaged/
Stuck. Inspect and replace as required.
|
SHIFTS DELAYED OR
ERRATIC (SHIFTS ALSO
HARSH AT TIMES) |
- Fluid Level Low/High.
- Throttle Linkage Misadjusted.
- Throttle Linkage Binding.
- Gearshift Linkage/Cable
Misadjusted.
- Fluid Filter Clogged.
- Governor Valve Sticking.
- Governor Seal Rings Worn/
Damaged.
- Clutch or Servo Failure.
- Front Band Misadjusted.
- Pump Suction Passage Leak.
|
- Correct fluid level and check for leaks if
low.
- Adjust linkage as described in service
section.
- Check cable for binding. Check for return
to closed throttle at transmission.
- Adjust linkage/cable as described in
service section.
- Replace filter. If filter and fluid contained
clutch material or metal particles, an
overhaul may be necessary. Perform lube
flow test.
- Inspect, clean or repair.
- Inspect/replace.
- Remove valve body and air test clutch,
and band servo operation. Disassemble
and repair transmission as needed.
- Adjust band.
- Check for excessive foam on dipstick
after normal driving. Check for loose pump
bolts, defective gasket. Replace pump
assembly if needed.
|
NO REVERSE (D RANGES
OK) |
- Gearshift Linkage/Cable
Misadjusted/Damaged.
- Park Sprag Sticking.
- Rear Band Misadjusted/Worn.
- Valve Body Malfunction.
- Rear Servo Malfunction.
- Front Clutch Burnt.
|
- Repair or replace linkage parts as
needed.
- Inspect and replace as necessary.
- Adjust band; replace.
- Remove and service valve body. Replace
valve body if any valves or valve bores are
worn or damaged.
- Remove and disassemble transmission.
Replace worn/damaged servo parts as
necessary.
- Remove and disassemble transmission.
Replace worn, damaged clutch parts as
required.
|
HAS FIRST/REVERSE
ONLY (NO 1-2 OR 2-3
UPSHIFT) |
- Governor Valve, Shaft, Weights or
Body Damaged/Stuck.
- Valve Body Malfunction.
- Front Servo/Kickdown Band
Damaged/Burned.
|
- Remove governor assembly and clean or
repair as necessary.
- Stuck 1-2 shift valve or governor plug.
- Repair/replace.
|
MOVES IN 2ND OR 3RD
GEAR, ABRUPTLY
DOWNSHIFTS TO LOW |
- Valve Body Malfunction.
- Governor Valve Sticking.
|
- Remove, clean and inspect. Look for
stuck 1-2 valve or governor plug.
- Remove, clean and inspect. Replace
faulty parts.
|
NO LOW GEAR (MOVES
IN 2ND OR 3RD GEAR
ONLY) |
- Governor Valve Sticking.
- Valve Body Malfunction.
- Front Servo Piston Cocked in
Bore.
- Front Band Linkage Malfunction
|
- Remove governor, clean, inspect and
repair as required.
- Remove, clean and inspect. Look for
sticking 1-2 shift valve, 2-3 shift valve,
governor plug or broken springs.
- Inspect servo and repair as required.
- Inspect linkage and look for bind in
linkage.
|
NO KICKDOWN OR
NORMAL DOWNSHIFT |
- Throttle Linkage Misadjusted.
- Accelerator Pedal Travel
Restricted.
- Governor/Valve Body Hydraulic
Pressures Too High or Too Low Due
to Sticking Governor, Valve Body
Malfunction or Incorrect Hydraulic
Control Pressure Adjustments.
- Valve Body Malfunction.
- Valve Body Malfunction.
|
- Adjust linkage.
- Floor mat under pedal, accelerator cable
worn or brackets bent.
- Perform hydraulic pressure tests to
determine cause and repair as required.
Correct valve body pressure adjustments as
required.
- Perform hydraulic pressure tests to
determine cause and repair as required.
Correct valve body pressure adjustments as
required.
- Sticking 1-2, 2-3 shift valves, or governor
plugs.
|
STUCK IN LOW GEAR
(WILL NOT UPSHIFT) |
- Throttle Linkage Misadjusted/
Stuck.
- Gearshift Linkage Misadjusted.
- Governor/Valve Body, Governor
Valve Stuck Closed; Loose Output
Shaft Support or Governor Housing
Bolts, Leaking Seal Rings or Valve
Body Problem (i.e., Stuck 1- 2 Shift
Valve/Gov. Plug).
- Front Band Out of Adjustment.
- Clutch or Servo Malfunction.
|
- Adjust linkage and repair linkage if worn
or damaged. Check for binding cable or
missing return spring.
- Adjust linkage and repair linkage if worn
or damaged.
- Check line and governor pressures to
determine cause. Correct as required.
- Adjust Band.
- Air pressure check operation of clutches
and bands. Repair faulty component.
|
CREEPS IN NEUTRAL |
- Gearshift Linkage Misadjusted.
- Rear Clutch Dragging/Warped
Welded.
- Valve Body Malfunction.
|
- Adjust linkage.
- Disassemble and repair.
- Perform hydraulic pressure test to
determine cause and repair as required.
|
BUZZING NOISE |
- Fluid Level Low
- Shift Cable Misassembled.
- Valve Body Misassembled.
- Pump Passages Leaking
- Cooling System Cooler Plugged.
- Overrunning Clutch Damaged.
|
- Add fluid and check for leaks.
- Route cable away from engine and bell
housing.
- Remove, disassemble, inspect valve
body. Reassemble correctly if necessary.
Replace assembly if valves or springs are
damaged. Check for loose bolts or screws.
- Check pump for porous casting, scores
on mating surfaces and excess rotor
clearance. Repair as required. Loose pump
bolts.
- Flow check cooler circuit. Repair as
needed.6. Replace clutch.
|
SLIPS IN REVERSE ONLY |
- Fluid Level Low.
- Gearshift Linkage Misadjusted.
- Rear Band Misadjusted.
- Rear Band Worn.
- Hydraulic Pressure Too Low.
- Rear Servo Leaking.
- Band Linkage Binding.
|
- Add fluid and check for leaks.
- Adjust linkage.
- Adjust band.
- Replace as required.
- Perform hydraulic pressure tests to
determine cause.
- Air pressure check clutch-servo operation
and repair as required.
- Inspect and repair as required.
|
SLIPS IN FORWARD
DRIVE RANGES |
- Fluid Level Low.
- Fluid Foaming.
- Throttle Linkage Misadjusted.
- Gearshift Linkage Misadjusted.
- Rear Clutch Worn.
- Low Hydraulic Pressure Due to
Worn Pump, Incorrect Control
Pressure Adjustments, Valve Body
Warpage or Malfunction, Sticking
Governor, Leaking Seal Rings,
Clutch Seals Leaking, Servo Leaks,
Clogged Filter or Cooler Lines
- Rear Clutch Malfunction, Leaking
Seals or Worn Plates.
- Overrunning Clutch Worn, Not
Holding (Slips in 1 Only).
|
- Add fluid and check for leaks.
- Check for high oil level, bad pump
gasket or seals, dirt between pump halves
and loose pump bolts. Replace pump if
necessary.
- Adjust linkage.
- Adjust linkage.
- Inspect and replace as needed.
- Perform hydraulic and air pressure tests
to determine cause.
- Air pressure check clutch-servo operation
and repair as required.
- Replace Clutch.
|
SLIPS IN LOW GEAR "D"
ONLY, BUT NOT IN 1
POSITION |
Overrunning Clutch Faulty. |
Replace overrunning clutch. |
GROWLING, GRATING OR
SCRAPING NOISES |
- Drive Plate Broken.
- Torque Converter Bolts Hitting
Dust Shield.
- Planetary Gear Set Broken/
Seized.
- Overrunning Clutch Worn/Broken.
- Oil Pump Components Scored/
Binding.
- Output Shaft Bearing or Bushing
Damaged.
- Clutch Operation Faulty.
- Front and Rear Bands
Misadjusted.
|
- Replace.
- Dust shield bent. Replace or repair.
- Check for debris in oil pan and repair as
required.
- Inspect and check for debris in oil pan.
Repair as required.
- Remove, inspect and repair as required.
- Remove, inspect and repair as required.
- Perform air pressure check and repair as
required.
- Adjust bands.
|
DRAGS OR LOCKS UP |
- Fluid Level Low.
- Clutch Dragging/Failed
- Front or Rear Band Misadjusted.
- Case Leaks Internally.
- Servo Band or Linkage
Malfunction.
- Overrunning Clutch Worn.
- Planetary Gears Broken.
- Converter Clutch Dragging.
|
- Check and adjust level.
- Air pressure check clutch operation and
repair as required.
- Adjust bands.
- Check for leakage between passages in
case.
- Air pressure check servo operation and
repair as required.
- Remove and inspect clutch. Repair as
required.
- Remove, inspect and repair as required
(look for debris in oil pan).
- Check for plugged cooler. Perform flow
check. Inspect pump for excessive side
clearance. Replace pump as required.
|
WHINE/NOISE RELATED
TO ENGINE SPEED |
- Fluid Level Low.
- Shift Cable Incorrect Routing.
|
- Add fluid and check for leaks.
- Check shift cable for correct routing.
Should not touch engine or bell housing.
|
TORQUE CONVERTER
LOCKS UP IN SECOND
AND/OR THIRD GEAR |
Lockup Solenoid, Relay or Wiring
Shorted/Open. |
Test solenoid, relay and wiring for
continuity, shorts or grounds. Replace
solenoid and relay if faulty. Repair wiring
and connectors as necessary |
HARSH 1-2 OR 2-3
SHIFTS |
Lockup Solenoid Malfunction. |
Remove valve body and replace solenoid
assembly. |
NO START IN PARK OR
NEUTRAL |
- Gearshift Linkage/Cable
Misadjusted.
- Neutral Switch Wire Open/Cut.
- Neutral Switch Faulty.
- Neutral Switch Connect Faulty.
- Valve Body Manual Lever
Assembly Bent/Worn/Broken.
|
- Adjust linkage/cable.
- Check continuity with test lamp. Repair
as required.
- Refer to service section for test and
replacement procedure.
- Connectors spread open. Repair.
- Inspect lever assembly and replace if
damaged.
|
NO REVERSE (OR SLIPS
IN REVERSE) |
- Direct Clutch Pack (front clutch)
Worn.
- Rear Band Misadjusted.
- Front Clutch Malfunctioned/Burnt.
|
- Disassemble unit and rebuild clutch
pack.
- Adjust band.
- Air pressure test clutch operation.
Remove and rebuild if necessary.
|
OIL LEAKS (ITEMS
LISTED REPRESENT
POSSIBLE LEAK POINTS
AND SHOULD ALL BE
CHECKED. |
- Speedometer Adapter Leaks.
- Fluid Lines and Fittings Loose/
Leaks/Damaged.
- Filler Tube (where tube enters
case) Leaks/Damaged.
- Pressure Port Plug Loose
Loose/Damaged.
- Pan Gasket Leaks.
- Valve Body Manual Lever Shaft
Seal Leaks/Worn.
- Rear Bearing Access Plate Leaks.
- Gasket Damaged or Bolts are
Loose.
- Adapter/Extension Gasket
Damaged Leaks/Damaged.
- Neutral Switch Leaks/Damaged.
- Converter Housing Area Leaks.
- Pump Seal Leaks/Worn/
Damaged.
- Torque Converter Weld
Leak/Cracked Hub.
- Case Porosity Leaks.
|
- Replace both adapter seals.
- Tighten fittings. If leaks persist, replace
fittings and lines if necessary.
- Replace O-ring seal. Inspect tube for
cracks in tube.
- Tighten to correct torque. Replace plug
or reseal if leak persists.
- Tighten pan screws to 150 inch pounds.
If leaks persist, replace gasket. Do no over
tighten screws.
- Replace shaft seal.
- Replace gasket. Tighten screws.
- Replace bolts or gasket or tighten both.
- Replace gasket.
- Replace switch and gasket.
- 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.
- Replace seal.
- Replace converter.
- Replace case.
|