Hummer H1 (2006+). Manual - part 20

1-32

General Information, Lubrication and Maintenance

________________

Figure 1-20:   Oil Filter/Drain Plug Location

Figure 1-21:   Engine Oil Fill Location

Fuel Filter Service

Replace the filter element every 6,000 mi (9,600 km), or annually, whichever occurs first (Figure-1-22). See “Purging Air From
Diesel Filter” (Section 3). 

Figure 1-22:   Fuel Filter Location 

ADAPTER

OIL PAN

DRAIN PLUG

OIL FILTER

OIL FILLER CAP

FUEL FILTER

FUEL FILTER

PRIMING PUMP

_______________

 General Information, Lubrication and Maintenance  1-33

5745804

Transmission Fluid

Figure 1-23:   Transmission Dipstick Location 

Replace the transmission fluid filter each time the fluid is changed. Refill the transmission with Dexron

®

 III afterward.

Check transmission fluid level at least once each month. Procedure is as follows:

1.

Drive the vehicle until the transmission fluid is at normal operating temperature. Fluid must be hot to obtain accurate reading.

2.

Position the vehicle on a level surface.

3.

Shift the transmission into Park.

4.

Operate the engine at curb idle speed.

5.

Remove the transmission dipstick and check the level (Figure-1-23). Correct level is within the crosshatch marks on the dipstick.

6.

If the fluid level is too high, remove the excess through the fill tube using a suction gun and 3/16-in. teflon tubing. If level is
low, check for leaks and, if OK, add fluid in 1-2 ounce increments until level is correct.

CAUTION: Do not overfill the transmission. The excess fluid will be churned into foam resulting in overflow from the fill and
vent tubes, slip and flare during upshifts, fluid breakdown and eventual clutch failure.

7.

Check the fluid color and the condition. Normal color ranges from dark red to light pink. Fluid that is dark brown, black, or
orange and full of bubbles indicates a problem that may require overhaul.

Transfer Case Fluid

Check transfer case fluid level every 6,000 mi (9 700 km), or semiannually, whichever comes first. Remove fill plug and gasket.
Level should be within 1/2 in. (12.7 mm) of fill plug opening when transfer case is level. Install fill plug and gasket, and tighten to
15-25 lb-ft (20-33 N•m). Change fluid every 12,000 mi (19 000 km) or annually, whichever occurs first (Figure-1-24).

Inspect rubber plug in the shift rail roll pin access passage located near the shift lever for leakage. Replace plug if leakage is
present.

Figure 1-24:   Transfer Case Fill/Drain Plug Location

TRANSMISSION DIPSTICK

AND FILL TUBE

FILL PLUG

DRAIN PLUG

1-34

General Information, Lubrication and Maintenance

________________

Axle and Geared Hub

Check axle and hub lubricant condition and level every 6,000 mi (9,700 km) or semiannually, whichever occurs first.

Geared hub level should be within 1/2 in. (12.7 mm) of fill plug opening when lubricant is cold, or to plug level when hot.

Axle level should be within 1/4 in. (6.4 mm) of fill plug opening when lubricant is cold, or to plug level when hot (Figures 1-25
and 1-26).

Change axle and hub lubricant when contaminated by water or foreign material.

The geared hubs use GL-5, SAE 80W-90 or 75W-90 gear lubricant only.

For the axles, use only HUMMER H1 Synthetic Gear Lube  75W-90 with friction modifier.

Figure 1-25:   Geared Hub Fill/Drain Plug Locations

Figure 1-26:   Axle Fill/Drain Plug Locations

LUBRICATION POINT

FILL PLUG

DRAINPLUG

LUBRICATION

 POINT

FILL PLUG

DRAINPLUG

12-1-05

_______________

 General Information, Lubrication and Maintenance  1-35

5745804

Geared Fan Drive

CAUTION: If the fluid level is checked when the unit is hot, some of the expanded fluid will run out and create a low fluid condi-
tion.

The fluid level in the reservoir must be checked every 6,000 mi (9,700 km) or semiannually, whichever occurs first and topped off
using HUMMER H1 Synthetic Gear Lube 75W-90 with friction modifier. Remove the fill plug when the unit is cold and ensure
that the fluid is even with the bottom of the fill plug hole  (Figure-1-27). The coupler shaft CV joints must be greased every 6,000
mi (9,700 km) or semiannually, whichever occurs first with a multipurpose, NLGI-LB grade chassis grease. The coupler shaft has
a CV joint at the GFD end and one at the engine crankshaft end. Each CV joint contains two grease zerks, although only one zerk
needs to be greased per joint. The second zerk is used to give an optional location depending on the position of the shaft when the
engine stopped. This should lessen the need to bar the engine over to gain access to the zerks. Grease should be applied, using a low
pressure grease gun, to the joint until old grease can be seen exiting around the sleeve on the shaft. Wipe the excess grease from the
shaft when finished (Figure-1-28). 

NOTE: It will be normal for some grease to exit the CV joint seals during engine operation, DO NOT replace the CV joints for this
condition.

Figure 1-27:   GFD Fill and Drain Plug

FILL

PLUG

DRAIN

PLUG

GEARED

FAN DRIVE

6-1-05