Hummer H2. Manual - part 2599

band. These spring forces help control the 2-4 band release.

1-2 Accumulator Assembly 

The 2nd clutch fluid also exhausts from the 1-2 accumulator assembly. The spring force and the accumulator 
fluid pressure move the accumulator piston to assist the 2nd clutch fluid exhaust. 

Accumulator Valve 

As the accumulator fluid is filling the 1-2 accumulator assembly, the accumulator valve regulates the D4 fluid 
into the accumulator fluid circuit. This regulation, biased by torque signal fluid pressure and spring force, helps 
control the movement of the 1-2 accumulator piston. The 2nd clutch fluid exhaust, and the 2-4 band release. 

1-2 Upshift Checkball (#8) 

Exhausting the 2nd clutch fluid pressure unseats the ball and is routed through the 2nd fluid circuit. 

Lo and Reverse Clutch Applies 

Lo Overrun Valve 

The Lo/1st fluid is regulated through the lo overrun valve and into the Lo/reverse fluid circuit in order to control 
the lo and reverse clutch apply. 

Lo and Reverse Piston 

The Lo/reverse fluid pressure acts on the inner area of the piston in order to move the piston and in order to 
apply the lo and reverse clutch plates. 

Overrun Clutch Applied 

The overrun clutch remains applied in manual first in order to provide engine compression braking. 

Pressure Control (PC) Solenoid Valve 

Similar to manual second, the PCM output signal to the PC solenoid valve increases the operating range of the 
torque signal fluid pressure. This provides the increased line pressure for the additional torque requirements 
during the engine compression braking and the increased engine loads. 

3-2 Downshift Control Solenoid Valve and the 3-2 Control Valve 

In first gear the solenoid is OFF, the AFL fluid is blocked by the solenoid, and the 3-2 signal fluid exhausts 
through the solenoid and the spring force opens the 3-2 control valve.

 

2004 Hummer H2 

2004 TRANSMISSION/TRANSAXLE Automatic Transmission - Overhaul - 4L60-E/4L65-E

  

Fig. 334: Manual First Gear 
Courtesy of GENERAL MOTORS CORP.

 

2004 Hummer H2 

2004 TRANSMISSION/TRANSAXLE Automatic Transmission - Overhaul - 4L60-E/4L65-E

  

FLUID PASSAGES 

Fig. 335: Pump Body Fluid Passages (Pump Cover Side) 
Courtesy of GENERAL MOTORS CORP. 

Callouts For Fig. 335 

Callout

Component Name

1

Suction (intake)

2

Decrease

2

Decrease

3

Line

3

Line

 

2004 Hummer H2 

2004 TRANSMISSION/TRANSAXLE Automatic Transmission - Overhaul - 4L60-E/4L65-E

  

3

Line

4

Converter Feed

4

Converter Feed

4

Converter Feed

5

Release

7

To Cooler

8

Lube from Cooler

11

Torque Signal

16

Reverse Input

16

Reverse Input

29

3-4 Clutch

37

Overrun Clutch

43

Exhaust

43

Exhaust

43

Exhaust

43

Exhaust

45

Vent

46

Seal Drain

47

Void

47

Void

48

Regulated Apply

 

2004 Hummer H2 

2004 TRANSMISSION/TRANSAXLE Automatic Transmission - Overhaul - 4L60-E/4L65-E