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