Automatic Transmission - 4L80-E/4L85-E (Overhaul): Other Chevrolet Silverado 3500

Low and Reverse Band Servo Piston Pin Check

Tools Required

1. J 21370-10 Band Apply Pin Gage. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 38737 Band Apply Pin Checking Tool. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Install the J 21370-10 into the low and reverse band servo pin bore.
2. Position the J 38737 over the low and reverse band servo bore with the hex hub facing the parking pawl linkage.
3. Fasten the J 38737 to the case with two low and reverse band servo cover bolts (61). Tighten: Tighten the bolts to 24 N.m (18 lb ft).
4. Verify that the J 21370-10 moves freely in the J 38737 and in the low and reverse band servo pin bore.
5. In order to determine the correct low and reverse band servo piston pin length, tighten the hex hub of the J 38737 . Tighten: Tighten the hex hub of the J 38737 to 34 N.m (25 lb ft).
6. Observe the lands on the J 21370-10 in order to determine which land is even with the top edge of the J 38737 . Note the letter (A, B or C) stamped on the J 21370-10 .
7. Refer to the Low and Reverse Band Servo Piston Pin Specification chart, in the «Transmission General Specifications»(ref-186420-S36088907062005083000000) , in order to determine the correct pin length to use.

Front End Play Check

Tools Required

1. J 8001 Dial Indicator Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 25025-B Guide Pin Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
3. J 28585 Snap Ring Remover. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Assemble the J 25025-B by attaching the threaded rod and the dial indicator holder to one of the bolt holes on the transmission case assembly (7).
2. Assemble the J 8001-3 onto the dial indicator holder. Index the J 8001-3 to the end of the turbine shaft (502).
3. Eliminate any slack by pressing down on the turbine shaft (502).
4. Using the J 28585 , apply upward pressure on the output carrier assembly to remove free play in the retainer ring.
5. Set the J 8001-3 to 0.
6. Pull up on the turbine shaft (502) while holding up the output carrier assembly with the J 28585 . The correct end play is between 0.102-0.559 mm (0.004-0.022 in).
7. Record this measurement for future reference.
8. Remove the tools.

Rear Unit End Play Check

Tools Required

1. J 8001 Dial Indicator Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 25025-B Guide Pin Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Assemble the J 25025-B by attaching the threaded rod and the dial indicator holder to one of the case extension bolt holes on the transmission case assembly (7).
2. Push in the output shaft assembly (671) to remove any slack.
3. Assemble the J 8001-3 onto the dial indicator holder. Index the J 8001-3 to the end of the output shaft (671).
4. Set the J 8001-3 to 0.
5. Move the output shaft (671) in and out, noting the amount of end play. The correct end play is between 0.127-0.635 mm (0.005-0.025 in).
6. Record this measurement for future reference.
7. Remove the tools.

Tools Required

J 38358-A Forward Clutch Assembly Remover/Installer. See Special Tools and Equipment .

J 38733 Direct Clutch Assembly Remover/Installer. See Special Tools and Equipment .

Scheme 733

Using the J 38733 , remove the direct clutch housing assembly (623).

J 36850 Assembly Lubricant. See Special Tools and Equipment .

J 41505 Output Shaft Seal Installer. See Special Tools and Equipment .

1. J 28585 Snap Ring Remover. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 36850 Assembly Lubricant. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

Tools Required

1. J 8001 Dial Indicator Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 25025-B Dial indicator Post Guide Pin Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Assemble the J 25025-B by attaching the threaded rod and the dial indicator holder to one of the case extension bolt holes on the transmission case (7).
2. Push the output shaft assembly (671) in to remove any slack.
3. Install the J 8001-3 on the dial indicator holder. Index the J 8001-3 to the end of the output shaft (671).
4. Set the J 8001-3 to 0.
5. Move the output shaft (671) in and out, noting the amount of end play. End Play Specification: The correct end play is 0.127-0.635 mm (0.005-0.025 in). If the end play is not correct, change the output shaft selective thrust washer (674). Refer to the «Output Shaft Selective Thrust Washer Specifications»(ref-186420-S23231640832005083000000) .
6. Remove the tools.

J 23093 Center Support Alignment Tool. See Special Tools and Equipment .

Direct Clutch Piston Travel Check

Tools Required

1. J 8001 Dial Indicator Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 7057 Dial Indicator Plunger Extension. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Attach the J 7057 (not visible in the illustration) to the J 8001-3 .
2. Using the J 8001-1 , mount the J 8001-3 to the transmission case through the opening in the case barrel. Place the J 7057 onto the direct clutch piston assembly.
3. Index the J 8001-3 . Set the dial to 0.
4. Apply 80 psi of air pressure to the direct clutch fluid passage (3rd/Reverse), in the case bottom, in order to actuate the direct clutch piston. Refer to «Fluid Passages»(ref-186420-S37758647662005083000000) , Case Fluid Passages illustration.
5. Measure the direct clutch piston travel. Piston Travel Specification: The piston travel should be 1.27-4.369 mm (0.050-0.172 in).
6. Remove the tools.

Forward Clutch Piston Travel Check

Tools Required

1. J 8001 Dial Indicator Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 26900-13 Magnetic Indicator Base. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Remove the overdrive carrier retainer ring (522).
2. Remove the turbine shaft (502).
3. Place the turbine shaft (502) in a soft-jawed vice.
4. Install the forward clutch housing assembly (602) onto the turbine shaft (502).
5. Attach the J 8001-3 to the J 26900-13 .
6. Place an index finger over one side of the forward clutch fluid passage in the turbine shaft (502).
7. Apply air to the other side of the forward clutch fluid passage in the turbine shaft (502). Piston Travel Specification: The piston travel should be 1.27-4.369 mm (0.050-0.172 in).
8. Remove the tools.
9. Remove the forward clutch housing assembly (602) from the turbine shaft (502).

J 36850 Assembly Lubricant. See Special Tools and Equipment .

J 36850 Assembly Lubricant. See Special Tools and Equipment .

J 36850 Assembly Lubricant. See Special Tools and Equipment .

Transmission Oil Pump Body to Gear Face Clearance Check

1. Place a straight edge across the face of the oil pump body assembly (203) and the faces of the oil pump gears (204, 205).
2. Measure the clearance between the straight edge and the faces of the oil pump gears. The proper clearance is between 0.017-0.071 mm (0.0008-0.0028 in).

J 38693 Oil Pump Seal Installer. See Special Tools and Equipment .

J 25025-1 Guide Pins. See Special Tools and Equipment .

Tools Required

1. J 8001 Dial Indicator Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 25025-B Guide Pin Set. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
3. J 28585 Snap Ring Remover. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Assemble the J 25025-B by attaching the threaded rod and the dial indicator holder to one of the bolt holes on the transmission case assembly (7).
2. Assemble the J 8001-3 onto the dial indicator holder. Index the J 8001-3 to the end of the turbine shaft (502).
3. Eliminate any slack by pressing down on the turbine shaft (502).
4. Using J 28585 , apply upward pressure on the output carrier assembly to remove free play in the retainer ring.
5. Set the J 8001-3 to 0.
6. Pull up on the turbine shaft (502) while holding up the output carrier assembly with the J 28585 . End Play Specification: The correct end play is 0.102-0.559 mm (0.004-0.022 in).
7. Remove the tools from the transmission.
8. If the front end play measurement is incorrect, refer to the «Overrun Clutch Housing Selective Thrust Washer Specifications»(ref-186420-S29941047222005083000000) . Choose a new selective thrust washer based on the original selective washer and the information contained in the table.
9. Correct the end play by changing the overrun clutch housing selective thrust washer.

Low and Reverse Band Servo Apply Piston Pin Check

Tools Required

1. J 21370-10 Band Apply Pin Gauge. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .
2. J 38737 Band Apply Pin Checking Tool. See «Special Tools and Equipment»(ref-186420-S27067422292005083000000) .

1. Install the J 21370-10 into the low and reverse band servo pin bore.
2. Position the J 38737 over the low and reverse band servo bore with the hex hub facing the parking pawl linkage.
3. Fasten the J 38737 to the case with 2 low and reverse band servo cover bolts (61). Tighten: Tighten the bolts to 24 N.m (18 lb ft).
4. Verify that the J 21370-10 moves freely in the J 38737 and in the low and reverse band servo pin bore.
5. Tighten the hex hub of the J 38737 . Tighten: Tighten the hex hub of the J 38737 to 34 N.m (25 lb ft).
6. Observe the lands on the J 21370-10 in order to determine which land is even with the top edge of the J 38737 . Note the letter (A, B or C) stamped on the J 21370-10 .
7. Refer to the Low and Reverse Band Servo Piston Pin Specification chart, in the «Transmission General Specifications»(ref-186420-S36088907062005083000000) , in order to determine the correct pin length to use.
8. Remove the tools.

J 25025-5 Guide Pin. See Special Tools and Equipment .

J 21366 Converter Holding Strap. See Special Tools and Equipment .

Park or Neutral - Engine Running

When you start the vehicle, the oil pump generates fluid flow from the transmission sump through the filter and into the pump. Filtered transmission fluid is directed to the pressure regulator valve.

Scheme 734

Reverse

When you move the gear selector lever to the Reverse position, the manual valve blocks the line fluid pressure from entering the Drive, D321, D21 and Lo fluid circuits. These fluids exhaust at the manual valve. The manual valve allows the line fluid pressure to enter the Reverse, PRN, PRND43, and PRND4 hydraulic circuits.

Scheme 735

Overdrive Range, First Gear

When you move the gear selector lever to the Overdrive position, the manual valve is repositioned in order to allow line pressure to flow in its respective circuits.

Scheme 736

Overdrive Range, Second Gear

In order to obtain second gear, the PCM receives input signals from the transmission speed sensors (input and output), the Throttle Position (TP) Sensor, and from other engine sensors. These signals determine when to de-energize the 1-2 Shift Solenoid (SS) Valve.

Scheme 737

Overdrive Range, 4-3 Downshift

In order to obtain the 4-3 downshift, the PCM receives an input signal from the TP Sensor at increased throttle openings. This causes the PCM to de-energize the 1-2 Shift Solenoid (SS) Valve.

Scheme 738

Overdrive Range, 3-2 Downshift

In order to obtain the 3-2 downshift, the PCM receives an input signal from the TP Sensor at increased throttle openings. This causes the PCM to de-energize the 2-3 Shift Solenoid (SS) Valve.

Scheme 739

Manual Third Gear

Manual Third can be used in order to increase the performance of the vehicle by allowing higher engine RPM for more torque. Manual Third will also provide vehicle engine compression braking when descending slight grades. Manual Third can be selected at any vehicle speed. The transmission will downshift into third gear at any vehicle speed.

Scheme 740

Manual Second Gear

Use the Manual 3-2 downshift in order to provide increased engine braking over Manual Third. Move the shift selector from the Manual Third position to the Manual Second position. You can select Manual Second at any vehicle speed or from any gear range in order to downshift the transmission into second gear.

Scheme 741

Manual First Gear

Use Manual First for maximum engine braking when the car is descending steep grades. Select Manual First at any vehicle speed. However, the transmission will first operate in Manual First - Second Gear condition until the vehicle speed slows sufficiently.

Scheme 742

Scheme 743

Scheme 744

Scheme 745

Scheme 746

Scheme 747

Scheme 748

Scheme 749

Scheme 750

Scheme 751