Hummer H2. Manual - part 2626

Fig. 40: Identifying Manual Shaft Seal 
Courtesy of GENERAL MOTORS CORP. 

Installation 

1. Carefully slide a new selector shaft seal (1) over the selector shaft (2) with the wide face of the steel case 

facing outward. See Fig. 40 . Position the seal so that it is starting to enter the seal bore.  

2. Obtain Selector Shaft Seal Installer and remove the inner sleeve so that the tool will slide over the 

selector shaft.  

3. Slide the Seal Installer into position so that the end of the tool contacts the seal being installed. Use a 

mallet to strike the Seal Installer and drive the new seal into the seal bore until it is seated at the bottom of 
the bore.  

4. Install the PNP Switch. See PARK/NEUTRAL POSITION SWITCH . Lower the vehicle.  

5. Fill the transmission to the proper level with transmission fluid. See RECOMMENDED FLUIDS and 

CHECKING FLUID LEVEL & CONDITION . 

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2

  

PARK/NEUTRAL POSITION SWITCH 

Removal 

1. Apply the Parking brake. Shift the transmission into Neutral.  

2. Raise and suitably support the vehicle.  

3. Remove nut securing the transmission control lever to the manual shaft. Remove transmission control 

lever from manual shaft.  

4. Disconnect the Park/Neutral Position (PNP) switch electrical connectors.  

5. Remove the PNP switch bolts.  

6. Remove the PNP switch from the manual shaft. If the PNP switch did not slide off the manual shaft, file 

the outer edge of the manual shaft in order to remove any burrs.  

Installation 

1. Install the PNP switch to the transmission manual shaft by aligning the switch hub flats with the manual 

shaft flats.  

2. Slide the PNP switch onto the transmission manual shaft until the switch mounting bracket contacts the 

mounting bosses on the transmission. 

3. Install the PNP switch bolts finger tight.  

4. Install park/neutral position switch aligner onto the PNP switch. See Fig. 41 . Ensure that the two slots on 

the switch where the manual shaft is inserted are lined up with the lower two tabs on the tool.  

5. Rotate the tool until the upper locator pin on the tool is lined up with the slot on the top of the switch. 

Tighten the bolts to specification. See TORQUE SPECIFICATIONS .  

6. Remove the park/neutral position switch aligner from the switch. If installing a new switch, remove the 

positive assurance bracket at this time.  

7. Connect the PNP switch electrical connectors.  

8. Install the transmission control lever to the manual shaft with the nut. Tighten the nut to specification. See 

TORQUE SPECIFICATIONS .  

9. Lower the vehicle.  

10. Check the switch for proper operation. The engine must start in the Park (P) or Neutral (N) positions 

only. If proper operation of the switch can not be obtained, replace the switch.  

NOTE:

Tools required: Park/Neutral Position Switch Aligner (J-41364-A). 

NOTE:

If a NEW PNP switch is being installed, the switch will come with a positive 
assurance bracket. The positive assurance bracket aligns the new switch 
in its proper position for installation and the use of the park neutral switch 
aligner will not be necessary. 

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2

  

Fig. 41: Adjusting Park/Neutral Position Switch 
Courtesy of GENERAL MOTORS CORP. 

PRESSURE REGULATOR 

Removal 

1. Remove the transmission oil pan and filter. See DRAINING & REFILLING under LUBRICATION.  

2. Compress the reverse boost valve sleeve into the bore of the oil pump to release tension on the reverse 

boost valve retaining ring. See Fig. 42 .  

3. Remove the reverse boost valve retaining ring, then slowly release tension on the reverse boost valve 

sleeve.  

4. Remove the reverse boost valve sleeve (5) and the reverse boost valve (4). See Fig. 43 .  

5. Remove the pressure regulator isolator spring (3) and the pressure regulator valve spring (2). Remove the 

pressure regulator valve (1).  

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2

  

Fig. 42: Installed View Of Pressure Regulator 
Courtesy of GENERAL MOTORS CORP.

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2