Hummer H2. Manual — part 2360

Held in the release position by spring force, it directs converter feed fluid into the release fluid circuit. Also,
fluid returning from the converter in the apply fluid circuit is routed through the valve and into the cooler fluid
circuit.

Torque Converter

Release fluid pressure unseats the TCC apply checkball (#9), keeps the pressure plate released from the
converter cover and fills the converter with fluid. Fluid exits the converter between the converter hub and the
stator shaft in the apply fluid circuit.

Cooler and Lubrication System

Cooler fluid from the converter clutch apply valve is routed through the transmission fluid cooler and into the
lubrication fluid circuits.

Manual Valve

Controlled by the selector lever and the manual shaft, the manual valve is in the Park (P) position and directs
the line pressure into the PR (Park/Reverse) fluid circuit. Line pressure is blocked from entering any other fluid
circuit at the manual valve.

Lo and Reverse Clutch Applies

Lo and Reverse Clutch Piston

The PR fluid seats the lo and reverse clutch checkball (#10) and is orificed to the outer area of the piston.
Orificing the PR fluid around the #10 checkball helps control the lo and reverse clutch apply. Also, Lo/reverse
fluid pressure from the lo overrun valve acts on the inner area of the lo and reverse clutch piston in order to
increase the clutch holding capacity.

Lo Overrun Valve

The PR fluid pressure moves the valve against the spring force and fills the Lo/reverse fluid circuit. Lo/reverse
fluid is orificed (323) back to the lo overrun valve in order to assist the PR fluid in moving the valve against the
spring force. The spring force provides a time delay for the PR fluid filling the Lo/reverse fluid circuit. The
Lo/reverse fluid is routed to the inner area of the lo and reverse clutch piston in order to increase the holding
capacity of the clutch.

Transmission Fluid Pressure (TFP) Manual Valve Position Switch Assembly

The TFP manual valve position switch consists of five fluid pressure switches: D2 and D3 are normally closed
and D4, Lo and Rev are normally open. All fluid circuits routed to the assembly are empty and the TFP manual
valve position switch signals the PCM that the transmission is in either Park or Neutral.

Shift Solenoid Valves (1-2 and 2-3)

Both shift solenoid valves, which are normally open, are energized by the PCM and block fluid from
exhausting. This maintains the signal A fluid pressure at the 1-2 shift solenoid valve and signal B fluid pressure

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E (Introduction) - Hummer H2

at the 2-3 shift solenoid valve.

Shift Valves (1-2, 2-3 and 3-4)

Signal A fluid pressure holds the 1-2 shift valve in the downshift position and the 3-4 valve in the upshift (first
and fourth gear) position. The signal B fluid pressure from the 2-3 shift solenoid valve holds the 2-3 shift valve
train in the downshift position.

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E (Introduction) - Hummer H2

Fig. 464: Park - Engine Running
Courtesy of GENERAL MOTORS CORP.

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E (Introduction) - Hummer H2

NEUTRAL - ENGINE RUNNING

When the gear selector lever is moved to the Neutral position (N) from the Reverse position, the following
changes occur to the transmission hydraulic and electrical systems.

Manual Valve

In the Neutral position, the manual valve blocks the line pressure from entering any other fluid circuits. Reverse
and PR fluids exhaust past the manual valve.

Lo and Reverse Clutch Releases

Lo and Reverse Clutch Piston

PR and Lo/reverse fluids exhaust from the piston, thereby releasing the lo and reverse clutch plates. Exhausting
PR fluid unseats the lo and reverse clutch checkball (#10) for a quick exhaust.

Lo Overrun Valve

Spring force closes the valve when the PR fluid pressure exhausts. Lo/reverse fluid exhausts through the valve,
into the Lo/1st fluid circuit, past the 1-2 shift valve, into the Lo fluid circuit and through an exhaust port at the
manual valve.

Reverse Input Cutch Releases

Reverse Input Clutch Piston

Reverse input fluid pressure exhausts from the piston, through the boost valve, past the #3 checkball and to the
manual valve. With the reverse input fluid exhausted, the reverse input clutch plates are released and the
transmission is in Neutral.

Reverse Abuse Valve

Reverse fluid pressure exhausts and spring force closes the valve.

Boost Valve

Reverse input fluid pressure exhausts and line pressure returns to the normal operating range as in the Park and
Overdrive positions.

Reverse Input Checkball (#3)

Exhausting reverse input fluid unseats the ball for a quick exhaust through the reverse fluid circuit and past the
manual valve.

Transmission Fluid Pressure (TFP) Manual Valve Position Switch Assembly

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E (Introduction) - Hummer H2