Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 634

7A1–36 AUTOMATIC TRANSMISSION (4L30-E)

CHART 11: ENGINE FLARE AT SHIFTING DURING TURNING ONLY

(USUALLY WITH WARM ENGINE)

PERFORM PRELIMINARY INSPECTION FIRST!

PERFORM PRELIMINARY INSPECTION FIRST!

CHART 12: ENGINE FLARE DURING 1-2 OR 2-3 SHIFT

Check

line pressure

(  ) Refer to Parts List at the end of this Section.

Leak at transmission oil filter, gasket,
or wrong filter type

Replace transmission oil filter and
gasket

Check for band apply solenoid (323)
stuck

Check for servo piston (106) leaks

Check for 1-2 accumulator valve (320)
stuck

Normal line pressure

Use CHART 15a: POSSIBLE CAUSES OF
LOW LINE PRESSURE on page 7A1-39

Low line pressure

Refer to Line Pressure chart 

( 

in this Section.

)

AUTOMATIC TRANSMISSION (4L30-E) 7A1–37

CHART 13: SHUDDER ONLY DURING TORQUE CONVERTER CLUTCH (TCC) APPLYING

PERFORM PRELIMINARY INSPECTION FIRST!

YES

NO

Replace transmission fluid and filter (remove both pans) and flush
cooler lines.
Replace converter assembly and O-ring on turbine shaft.

Drive until whole drivetrain is at normal operating temperature.
–

Shudder is a SHORT BURST OF NOISE NORMALLY LESS THAN 1
SECOND IN DURATION, and can be induced by the following
maneuver:

TCC shudder is one of the most commonly misdiagnosed conditions in
an automatic transmission. The key to diagnosing TCC shudder is to
note when it happens and under what conditions. Once the TCC has
been fully applied, it is nearly impossible to make it shudder. TCC
shudder (short burst of noise normally less than 1 second) will only
occur during clutch applying. It is not a steady state condition.

From coast condition at 50 mph in “D” range (Normal mode), depress
the throttle to 1/4-1/3 throttle.
If present, shudder (short burst of noise normally less than 1 sec.) will
occur within 5 seconds together with TCC applying.
(TECH2 may be used to determine the exact time of TCC applying)

Perform mechanical inspection of
other drivetrain components.

7A1–38 AUTOMATIC TRANSMISSION (4L30-E)

CHART 14: POSSIBLE CAUSES OF TRANSMISSION NOISE

PERFORM PRELIMINARY INSPECTION FIRST!

CAUTION:

Before checking transmission for what is believed to be transmission noise,
ensure presence and positioning of insulating plugs, pads etc. Also make
sure that noise does not come from other drivetrain components.

1.

WHINE OR BUZZ:
–

Oil level low

–

Plugged or restricted oil filter

–

Damaged oil filter gasket

2.

KNOCKING NOISE FROM FRONT OF TRANSMISSION:
–

Loose bolts (Converter to flex plate)

–

Cracked or broken flex plate

–

Converter damaged

3.

KNOCKING NOISE WHILE DRIVING - MOSTLY ON ACCELERATION:
–

Transmission mount loose or broken

–

Cooler line mounts loose or broken

–

Cooler lines touching body or frame

4.

KNOCKING NOISE WHEN VEHICLE IS STATIONARY:
–

Loose flex plate mounting bolts

–

Cracked or broken flex plate

–

Damaged converter

AUTOMATIC TRANSMISSION (4L30-E) 7A1–39

CHART 15a: POSSIBLE CAUSES OF LOW LINE PRESSURE

ON-VEHICLE SERVICE

TRANSMISSION REMOVED

OK

OK

OK

OK

OK

OK

OK

OK

OK

OK

Small
valve
body

Oil
pump































(  ) Refer to Parts List at the end of this Section.

Check for loose bolts (4 & 5)

Check for pressure regulator valve (208) stuck

Check for boost valve (205) stuck

Check for intermediate oil passages to pressure regulator valve blocked

Check for defective oil pump (9, 201, 202 & 209)

Check for internal leaks
– Check balls missing or out of location in valve bodies
– Seals cut or damaged
– Gaskets defective, etc.

Check oil level

Check for defective throttle position sensor

Check for plugged, loose, or damaged oil filter (79)

Check for force motor plunger (404) stuck. (Remove force motor. Shake and listen for rattle.)

Check for feed limit valve (412) stuck