Automatic Transmission - 4L60-E/4L65-E (Introduction, Service & Replacement): Overhaul Chevrolet Silverado 3500

Accumulator Assembly, Spacer Plate, and Gaskets

Tools Required

1. J 25025-B Pump and Valve Body Alignment Pin Set. See «Special Tools and Equipment»(ref-184202-S17623355442005082200000) .
2. J 36850 Transjel Lubricant. See «Special Tools and Equipment»(ref-184202-S17623355442005082200000) .

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Scheme 533

1. Remove the transmission filter. Refer to «Automatic Transmission Fluid/Filter Replacement»(ref-184202-S21897449202005082200000) .
2. Remove the valve body. Refer to «Valve Body and Pressure Switch Replacement»(ref-184202-S03037521222005082200000) .
3. Remove the accumulator cover bolts.
4. Remove the 1-2 accumulator cover.
5. Remove the 1-2 accumulator cover (57) and pin.
6. Disassemble the 1-2 accumulator assembly (54, 56, 57, 104).
7. Inspect the 1-2 accumulator springs for cracks.
8. Remove the 1-2 accumulator piston seal (1) from the 1-2 accumulator piston.
9. Inspect the 1-2 accumulator piston for the following conditions: Porosity Cracks Scoring Nicks and scratches
10. Inspect the 1-2 accumulator cover for the following conditions: Porosity Cracks Scoring Nicks and scratches
11. Remove the spacer plate support bolts.
12. Remove the spacer plate support.
13. Remove the spacer plate to valve body gasket, the spacer plate and the spacer plate to transmission case gasket.
14. Remove the 3-4 accumulator piston (2).
15. Inspect the 3-4 accumulator spring for cracks.
16. Remove the 3-4 accumulator piston seal (1) from the 3-4 accumulator piston.
17. Inspect the 3-4 accumulator piston for the following conditions: Porosity Cracks Scoring Nicks and scratches

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Scheme 535

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Scheme 537

1. Install a new 3-4 accumulator piston seal (1) to the 3-4 accumulator piston.
2. Install the 3-4 accumulator pin (1) into the transmission case and retain the pin with J 36850 .
3. Install the 3-4 accumulator piston (2) onto the pin (1) in the transmission case. Ensure that the 3-4 accumulator piston legs face away from the transmission case.
4. Install the J 25025-B (2, 3) to the transmission case.
5. Install the spacer plate to transmission case gasket and the spacer plate to valve body gasket to the spacer plate; use J 36850 in order to retain the gaskets to the spacer plate. The case gasket is identified by a C. Be sure to place the case gasket on the transmission case side of the spacer plate. The valve body gasket is identified by a V. Be sure to place the valve body gasket on the valve body side of the spacer plate.
6. Ensure that the solenoid screens (1, 2) are in place on the spacer plate.
7. Place the check ball (3) on the spacer plate in the location shown.
8. Place the 3-4 accumulator spring (4) on the spacer plate.
9. Install the spacer plate and related components to the transmission.
10. Install the spacer plate support and the spacer plate support bolts. Tighten: Tighten the bolts to 11 N.m (97 lb in).
11. After installing the spacer plate support (2), look through the hole in the spacer plate to ensure that the check ball (1) has remained in the proper location.
12. Install a new 1-2 accumulator piston seal (1) to the 1-2 accumulator piston.
13. Assemble the 1-2 accumulator assembly (54, 56, 57, 104). Ensure that the piston legs face the accumulator cover.
14. Install the 1-2 accumulator cover (57) and pin.
15. Install the 1-2 accumulator cover and the accumulator cover bolts. Tighten: Tighten the bolts to 11 N.m (97 lb in).
16. Remove the J 25025-B from the transmission case.
17. Install the valve body. Refer to «Valve Body and Pressure Switch Replacement»(ref-184202-S03037521222005082200000) .
18. Install the transmission filter. Refer to «Automatic Transmission Fluid/Filter Replacement»(ref-184202-S21897449202005082200000) .

3-2 Shift Solenoid Valve Assembly

The 3-2 shift solenoid valve assembly is a normally-closed, 3-port, ON/OFF device that is used in order to improve the 3-2 downshift. The solenoid regulates the release of the 3-4 clutch and the 2-4 band apply.

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Scheme 539

The transmission pressure control solenoid is an electronic pressure regulator that controls pressure based on the current flow through its coil winding. The magnetic field produced by the coil moves the solenoid's internal valve which varies pressure to the pressure regulator valve.

The PCM controls the pressure control solenoid by commanding current between 0.1-1.1 amps. This changes the duty cycle of the solenoid, which can range between 5-95 percent, typically less than 60 percent. High amperage (1.1 amps) corresponds to minimum line pressure, and low amperage (0.1 amp) corresponds to maximum line pressure, if the solenoid loses power, the transmission defaults to maximum line pressure.

The PCM commands the line pressure values, using inputs such as engine speed and throttle position sensor voltage.

The pressure control solenoid takes the place of the throttle valve or the vacuum modulator that was used on past model transmissions.

Scheme 540

The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used to control torque converter clutch apply and release. When grounded (energized) by the powertrain control module (PCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the TCC solenoid valve into the apply position.

The 3-2 shift solenoid valve assembly is a normally-closed, 3-port, ON/OFF device that is used in order to improve the 3-2 downshift. The solenoid regulates the release of the 3-4 clutch and the 2-4 band apply.

Scheme 541

The purpose of the Automatic Transmission Secondary Fluid Pump Assembly (1) is to fill the forward clutch with fluid in order to keep it lightly applied. Maintaining the forward clutch hydraulic capacity will ensure rapid clutch engagement during the engine restart cycles, eliminating engine flare or sudden transmission engagement.

The secondary fluid pump assembly is a gerotor type pump with an airtight electrical motor. The motor has a built-in electromagnet compatibility (EMC) and is a permanent magnet stator with a wound rotor. The pump is a external/internal toothed constant displacement pump and has a built-in pressure relief valve (2). The pump assembly utilizes a replaceable 60-Micron filter (3) and does not require regular maintenance. The pump assembly mounts to the valve body and is submerged in the transmission fluid sump.

As the motor drives the pump gear, a low-pressure area is created between the gear teeth. The fluid volume is positively displaced, thereby creating suction at the pump inlet. As the fluid space between the rotating gears lessen, high-pressure fluid is created and supplied to the manual valve where it is directed into the forward clutch hydraulic circuit. A check valve installed in the valve body located at the pump outlet prevents fluid from the main transmission oil pump from flowing into the secondary fluid pump.

Vehicle Speed Sensor Assembly

The vehicle speed sensor (VSS) assembly provides vehicle speed information to the PCM. The VSS assembly is a permanent magnet (PM) generator. The PM generator produces a pulsing AC voltage as rotor teeth on the transmission output shaft pass through the sensor's magnetic field. The AC voltage level and the number of pulses increase as the speed of the vehicle increases. Output voltage varies with speed from a minimum of 0.5 volts at 100 RPM to more than 100 volts at 8,000 RPM. The PCM converts the pulsing voltage to vehicle speed. The PCM uses the vehicle speed signal to determine shift timing and TCC scheduling.