Chevrolet Silverado / GMC Sierra. Service manual — part 747

1. Turn the main function switch to the CODE position.

2. Record TESTED flow rate, temperature, cycle and seven-character flow code information

on repair order.

CLEAN-UP

IMPORTANT:

If power is interrupted prior to the recording of the
seven-character code, the code will be lost and the flow
rate test will need to be repeated.

The flow test must run for a minimum of 8-10 seconds
and be above 0.5 GPM for a code to be generated.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 23: View Of Main Power Switch & Main Function Switch
Courtesy of GENERAL MOTORS CORP.

1. Turn the main function switch (2) to the IDLE position and allow the supply vessel pressure

to dissipate.

2. Turn the main power switch (1) to the OFF position.

IMPORTANT: A small amount of water may drain from the bottom of the

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

3. Disconnect the supply and waste hoses and the 12-volt power source from the vehicle.

Fig. 24: Applying Shop Air Supply Hose To Quick-Disconnect
Courtesy of GENERAL MOTORS CORP.

4. Disconnect the air supply hose from J 45096 .

5. Dispose of the waste ATF in accordance with all applicable federal, state, and local

requirements.

AUTOMATIC TRANSMISSION FLUID LEAKS

unit when the air supply is disconnected. This is a normal
operation of the built-in water separator.

Checks

Causes

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

NO PARK OR DRIVE

HARSH GARAGE SHIFT

NO DRIVE IN ALL RANGES

Torque Converter (1)

Inspect for damage.

Torque Converter Housing
(203)

Inspect for porosity or damage.

Automatic Transmission Fluid
Pump Seal (5)

Inspect for cut, wear, or damage.

Checks

Causes

Output Shaft Assembly (70)

Inspect for a broken or damaged output shaft. Inspect for
worn splines.

Checks

Causes

1-2-3-4 and 3-5-R Clutch
Assembly (51)

Inspect for damaged or worn 1-2-3-4 clutch plates (408-
410).

Checks

Causes

4-5-6 (with Turbine Shaft)
Clutch Assembly (56)

Inspect for damaged or worn 4-5-6 clutch backing
plate (432).

Inspect for damaged 4-5-6 clutch (with turbine shaft)
housing assembly (441).

Output Carrier Assembly (68)

Inspect the carrier assembly for damaged pinion
gears, thrust washers, pins, and rollers.

Inspect for damaged thrust bearings (486 and 488).

Inspect for damaged sun gears (487 and 489).

Inspect the carrier assembly for damaged output
carrier rear sun gear thrust bearing (captured).

Output Carrier Thrust Bearing
Assembly (69)

Inspect the bearing for wear or damage.

Output Shaft Assembly (70)

Inspect for damaged internal gears (495 and 497).

Input Sun Gear Thrust Washer
(55)

Inspect the washer for wear or damage.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado