Chevrolet Silverado / GMC Sierra. Service manual — part 1012

This procedure checks the transmission fluid level, as well as the condition of the fluid itself.

Before checking the fluid level, perform the following:

1. Start the engine and park the vehicle on a level surface. Keep the engine running.

2. Apply the parking brake and place the shift lever in PARK (P).

3. Depress the brake pedal and move the shift lever through each gear range, pausing for about

3 seconds in each range. Then, move the shift lever back to PARK (P).

4. Allow the engine to idle 500-800 RPM for at least 1 minute. Slowly release the brake

pedal.

5. Keep the engine running and observe the transmission fluid temperature (TFT) using the

Driver Information Center (DIC) or a scan tool.

6. Using the TFT reading, determine and perform the appropriate check procedure. If the TFT

reading is not within the required temperature ranges, allow the vehicle to cool, or operate
the vehicle until the appropriate TFT is reached.

COLD CHECK PROCEDURE

1. Start the engine and locate the transmission dipstick at the rear of the engine compartment,

on the passenger's side of the vehicle.

2. Flip the handle up, and then pull out the dipstick and wipe the dipstick end with a clean rag

or paper towel.

3. Install the dipstick by pushing it back in the dipstick tube all the way, wait three seconds

and then pull it back out again.

NOTE:

Always use the proper automatic transmission fluid listed. Using
incorrect automatic transmission fluid may damage the vehicle.

IMPORTANT: Use the cold check procedure only as a reference to

determine if the transmission has enough fluid to be
operated safely until a hot check procedure can be made.
The hot check procedure is the most accurate method to
check the fluid level. Perform the hot check procedure at the
first opportunity.
Use this cold check procedure to check fluid level when the
TFT is between 27-32°C (80-90°F).

IMPORTANT: Always check the fluid level at least twice. Consistent

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

4. Keep the dipstick pointing down and check both sides of the dipstick, and read the lower

level. Repeat the check procedure to verify the reading.

5. Inspect the color of the fluid on the dipstick. Refer to Fluid Condition Inspection in this

procedure.

6. If the fluid level is below the COLD check line, add only enough fluid as necessary to bring

the level into the COLD line. It does not take much fluid, generally less than one pint
(0.5L). Do not overfill.

7. If the fluid level is in the acceptable range, push the dipstick back in all the way, then flip

the handle down to lock the dipstick in place.

8. Perform a hot check at the first opportunity after the transmission reaches a normal

operating temperature between 82-93°C (180-200°F).

HOT CHECK PROCEDURE

1. Start the engine and locate the transmission dipstick at the rear of the engine compartment,

on the passenger side of the vehicle.

2. Flip the handle up, and then pull out the dipstick and wipe the dipstick end with a clean rag

or paper towel.

3. Install the dipstick by pushing it back in the dipstick tube all the way, wait three seconds

and then pull it back out.

readings are important to maintaining proper fluid level. If
inconsistent readings are noted, inspect the transmission
vent assembly to ensure it is clean and unclogged.

IMPORTANT: Use this procedure to check the transmission fluid level

when the TFT is between 82-93°C (180-200°F). The ho t check
procedure is the most accurate method to check the fluid
level. The hot check should be performed at the first
opportunity in order to verify the cold check. The fluid level
rises as fluid temperature increases, so it is important to
ensure the transmission temperature is within range.

IMPORTANT: Always check the fluid level at least twice. Consistent

readings are important to maintaining proper fluid level. If
inconsistent readings are noted, inspect the transmission
vent assembly to ensure it is clean and unclogged.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

4. Keep the dipstick tip pointing down and check both sides of the dipstick. Read the lower

level. Repeat the check procedure to verify the reading.

5. Inspect the color of the fluid on the dipstick. Refer to Fluid Condition Inspection below.

6. A safe operating fluid level is within the HOT crosshatch band on the dipstick. If the fluid

level is not within the HOT band, and the transmission temperature is between 82-93°C
(180-200°F), add or drain fluid as necessary to bring the level into the HOT band. If the
fluid level is low, add only enough fluid to bring the level into the HOT band.

7. If the fluid level is low, add only enough fluid to bring the level into the HOT band. It does

not take much fluid, generally less than one pint (0.5L). Do not overfill. Also, if the fluid
level is low, inspect the transmission for leaks. Refer to Fluid Leak Diagnosis.

8. If the fluid level is in the acceptable range, push the dipstick back into the dipstick tube all

the way, and then flip the handle down to lock the dipstick in place.

9. If applicable and if the vehicle is equipped, reset the transmission oil life monitor only if the

fluid was changed.

FLUID CONDITION INSPECTION

Inspect the fluid color. The fluid should be red or dark brown.

If the fluid color is very dark or black and has a burnt odor, inspect the fluid and inside of
the bottom pan for excessive metal particles or other debris. A small amount of "friction"
material in the bottom pan is a "normal" condition. If large pieces and/or metal particles are
noted in the fluid or bottom pan, flush the oil cooler and cooler lines and overhaul the
transmission. If there are no signs of transmission internal damage noted, replace the fluid
filter assembly, repair the oil cooler, and flush the cooler lines.

Fluid that is cloudy or milky or appears to be contaminated with water indicates engine
coolant or water contamination. Refer to Engine Coolant/Water in Transmission.

LINE PRESSURE CHECK

IMPORTANT: To assist in reaching the correct temperature range of 82-93°

C (180-200°F), drive the vehicle in second gear at no more
than 65 mph until the desired temperature is reached.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

Fig. 2: Using Pressure Gage To Test Line Pressure
Courtesy of GENERAL MOTORS CORP.

SPECIAL TOOLS

J 21867 Pressure Gage

CHECK

1. Install a scan tool.

2. Start the engine.

3. Inspect the transmission for the proper fluid levels. Refer to Transmission Fluid Check.

CAUTION: Keep the brakes applied at all times in order to prevent

unexpected vehicle motion. Personal injury may result if
the vehicle moves unexpectedly.

IMPORTANT: Before performing the line pressure check, verify that the

transmission pressure control (PC) solenoid is operating
correctly.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado