Automatic Transmission - 4L80-E - Servicing: Maintenance Chevrolet Silverado 1500 HD

SERVICE INTERVALS

Check transmission fluid level at each engine oil change. Change the automatic transmission fluid and the filter at 50,000 miles.

Checking Fluid Level

1. Start the engine and operate the vehicle for 15 minutes or until the transmission fluid reaches an operating temperature of 180-200°F (82-93°C).
2. Park the vehicle on a level surface.
3. With your foot on the brake, move the shift lever through each gear range. Pause for about 3 seconds in each range, ending in Park.
4. Apply the parking brake and let the engine idle for 3 minutes.
5. Remove the transmission fluid level indicator. Wipe the indicator clean. Insert the indicator. Give the indicator a full twist in order to close.
6. Wait 3 seconds and remove the indicator.
7. Read both sides of the indicator. The fluid must be within the hot cross hatched area using the lowest level reading.

Checking Fluid Condition

Note. Diagnose transmission fluid conditions by color.

1. Check the fluid color. Is the fluid color Red? If so, go to next step. If not, go to step 11 .
2. Is the fluid level satisfactory? If so, system is okay. If not, go to next step.
3. Check the fluid. Is the fluid foamy? If so, go to step 8 . If not, go to next step.
4. Check the fluid level. The proper fluid level should be in the middle of the cross hatched area on the fluid indicator. Is the level high? If so, go to step 9 . If not, go to next step.
5. The fluid will be low. Add fluid to the proper fluid level. After repairs, go to next step.
6. Check for external leaks. Were any leaks found? If so, go to next step. If not, go to step 20 .
7. Correct the leak condition. After repairs, go to step 20 .
8. Is the fluid level too high? If so, go to next step. If not, go to step 10 .
9. Remove excess fluid to the proper fluid level. Is the fluid level satisfactory? If so, go to step 20 .
10. Check for contaminants in the fluid. Drain the fluid to determine the source of the contamination. Was the fluid drained? If so, go to step 15 .
11. Is the fluid color non transparent Pink? If so, go to next step. If not, go to step 13 .
12. Replace the cooler. After repairs, go to step 15 . NOTE: Transmission fluid may turn Dark with normal use. This does not always indicate oxidation or contamination.
13. The fluid color should be Light Brown. Is the fluid color Light Brown? If so, go to next step. NOTE: A very small amount of material in the bottom pan is a normal condition, but large pieces of metal or other material in the bottom pan require a transmission overhaul.
14. Drain the fluid to determine if the fluid is contaminated. Was the fluid contaminated? If so, go to next step. If not, go to step 18 .
15. Overhaul transmission. See appropriate OVERHAUL article. Is the overhaul procedure complete? If so, go to next step.
16. Using scan tool, press clear TRANS ADAPT function. Are the reset procedures complete? If so, go to next step.
17. Fill transmission with appropriate fluid to proper level. See «RECOMMENDED FLUIDS»(ref-154137-S09914930692003050600000) and «FLUID CAPACITIES»(ref-154137-S39758386132003050600000) . Is the procedure complete? If so, go to step 20 .
18. Change the fluid and the filter. See «DRAINING & REFILLING»(ref-154137-S36879676582003050600000) . After repairs, go to step 19 .
19. Are the reset procedures complete? If so, go to next step.
20. Is the fluid level satisfactory? If so, system okay. If not, go to step 1 .

RECOMMENDED FLUIDS

Manufacturer recommends Dexron(R) III ATF.

Draining

1. Raise and suitably support the vehicle.
2. Place a drain pan under the transmission oil pan.
3. Remove the oil pan drain plug, if equipped.
4. Allow the transmission fluid to drain completely.
5. Apply a small amount of sealant to the threads of the drain plug, if equipped.
6. Install the oil pan drain plug. Tighten the oil pan drain plug to specification. See «TORQUE SPECIFICATIONS»(ref-154137-S39198836352003050600000).
7. Remove the drain pan from under the transmission oil pan.
8. Support the transmission with a transmission jack.
9. Remove the transmission mount nuts. (Scheme 280)
10. Remove the transmission support bolts and nuts. (Scheme 281)
11. Remove the transmission support side bracket bolts and bracket.
12. Remove the transmission support.
13. Disconnect the range selector cable end (2) from the transmission range selector lever ball stud (1). (Scheme 282) NOTE: It is not necessary to remove the selector cable from the bracket.
14. Remove the transmission range selector cable bracket (2) bolts and bracket from the transmission. Reposition the bracket with cable. (Scheme 283)
15. Remove the oil pan bolts. (Scheme 284) NOTE: The transmission oil pan gasket is reusable. Inspect the gasket and replace as needed.
16. Remove the oil pan and gasket.
17. Remove the magnet from the bottom of the pan, if necessary.
18. Remove the oil filter. (Scheme 285)
19. Remove the filter neck seal.
20. Clean the transmission case and the oil pan gasket surfaces with solvent.

Scheme 280

Scheme 281

Scheme 282

Scheme 283

Scheme 284

Scheme 285

Refilling

1. Install the filter neck seal. (Scheme 285)
2. Install the oil filter.
3. Install the oil pan gasket to the pan. (Scheme 284)
4. Install the magnet into the bottom of the pan, if necessary.
5. Install the oil pan and bolts. Tighten the oil pan bolts to specification. See «TORQUE SPECIFICATIONS»(ref-154137-S39198836352003050600000).
6. Position the bracket with cable. Install the transmission range selector cable bracket (2) and bolts to the transmission. (Scheme 283) Tighten the selector bracket bolts to specification. See «TORQUE SPECIFICATIONS»(ref-154137-S39198836352003050600000).
7. Connect the range selector cable end (2) to the transmission range selector lever ball stud (1). (Scheme 282)
8. Install the transmission support. (Scheme 281)
9. Install the transmission support side bracket and bolts.
10. Install the transmission support bolts and nuts. Tighten the bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(ref-154137-S39198836352003050600000).
11. Install the transmission mount nuts. (Scheme 280) Tighten the nuts to specification. See «TORQUE SPECIFICATIONS»(ref-154137-S39198836352003050600000).
12. Remove the transmission jack.
13. Lower the vehicle.
14. Fill the transmission to the proper level with appropriate transmission fluid. See «FLUID CAPACITIES»(ref-154137-S39758386132003050600000).

OIL COOLER FLUSHING

Note. DO NOT use solutions that contain alcohol or glycol. Use of solutions that contain alcohol or glycol may damage flushing equipment, oil cooler components and/or transmission components.

Back Flush

1. Inspect the transmission oil cooler pipes for kinks or damage. Repair as necessary.
2. Connect the transmission oil cooler and line flusher to the oil cooler feed front connector. Use the Cooler Flushing Adapter (J 35944-200), if required. (Scheme 286)
3. Clip the discharge hose (2) onto the oil drain container.
4. Attach the flusher to the undercarriage of the vehicle with the hook provided and connect the flushing system feed supply hose (3) from the flusher to the rear connector oil cooler return pipe. Use the cooler flushing adapter, if required.
5. Turn the flusher water supply valve (1) to the ON position and allow water to flow through the oil cooler and pipes for 10 seconds to remove any remaining transmission fluid. If water does not flow through the oil cooler and pipes, the cause of the blockage must be diagnosed and the plugged component must be repaired or replaced. Continue with the cooler flushing and flow check procedure once the blockage is corrected.
6. Turn the flusher water supply valve (1) to the OFF position and clip the discharge hose onto a 5 gallon (19 L) pail with a lid, to avoid splashback. NOTE: Flushing for approximately 2 minutes in each cooler line direction will result in a total of about 8-10 gallons of waste fluid. This mixture of water and flushing fluid is to be captured in a bucket or similar container.
7. Turn the flusher water supply valve (1) to the ON position and depress the trigger (8) to mix cooler flushing solution into the water flow. Use the clip provided on the handle to hold the trigger (8) down. The discharge will foam vigorously when the solution is introduced into the water stream. (Scheme 287)
8. Flush the oil cooler and pipes with water and solution for 2 minutes. During this flush, attach the shop air supply 120 psi (825 kPa) to the flushing system feed air valve (2) located on the flusher, for 3-5 seconds at the end of every 15-20 second interval to create a surging action.
9. Release the trigger (8) and turn the flusher water supply valve (1) to the OFF position.

Scheme 286

Scheme 287

Forward Flush

1. Disconnect both hoses (3 and 5) from the oil cooler pipes and connect them to the opposite oil cooler pipe. This will allow the oil cooler and pipes to be flushed in the normal flow direction. (Scheme 286)
2. Repeat steps 6 and 7 of the BACK FLUSH procedure.
3. Release the trigger (8) of the transmission oil cooler and line flusher and allow water only to rinse the oil cooler and pipes for one minute. (Scheme 287)
4. Turn the flusher water supply valve (1) to the OFF position and turn OFF the water supply at the faucet.
5. Attach the shop air supply to the flushing system feed air valve (2) on the flusher and blow out the water from the oil cooler and pipes. Continue, until no water comes out of the discharge hose.