Hummer H1 (1992-1998). Manual — part 17

2-18. CONNECTING ROD AND PISTON REPAIR (Cont’d)

2-57

2-19. CAMSHAFT, TIMING CHAIN, AND DRIVE GEARS REPAIR

This task covers:

a. Cleaning

b. Inspection

INITIAL SETUP

Tools

Equipment Condition

General mechanic’s tool kit:

Engine disassembled into subassemblies

automotive (Appendix E, Item 1)

(para. 2-15).

Micrometer (Appendix E, Item 16)
“V” blocks (Appendix E, Item 21)
Dial indicator (Appendix E, Item 10)

Manual References

Clean all components in accordance with para. 2-9.

b. Inspection

1.

2.

3.
4.

5.

6.
7.

NOTE

●

For general inspection instructions, refer to para. 2-10.

●

All lifters must be replaced when replacing camshaft.

Inspect camshaft bearing journals (7) and lobes (8) for damage. Replace camshaft (6) if damaged.
Measure diameter of bearing journals (7) using outside micrometer. Replace camshaft (6) if any
bearing journal (7) is out of specification (table 2-2 or 2-3).
Support camshaft (6) on "V" blocks.
Using dial indicator and “V" blocks, measure cam lobe (8) lift. Replace camshaft (6) if any cam
lobe (8) is out of specification (table 2-2 or 2-3).
Inspect crankshaft sprocket (9), camshaft sprocket (3), pump drive gear (10), and pump driven
gear (1) for damage. Replace any gear or sprocket if damaged.
Inspect timing chain (2) for cracks, breaks, or binding. Replace if cracked, broken, or binding.
Inspect camshaft thrust plate (4) and spacer (5) for damage. Replace if damaged.

2-58

2-19. CAMSHAFT, TIMING CHAIN, AND DRIVE GEARS REPAIR (Cont’d)

2-59

2-20.

TIMING GEAR COVER REPAIR

This task covers:

a. Cleaning

b. Inspection

INITIAL SETUP

Tools

Equipment Condition

General mechanic’s tool kit:

Engine disassembled into subassemblies

automotive (Appendix E, Item 1)

(para. 2-15).

Manual References

Clean all components in accordance with para. 2-9.

NOTE

For general inspection instructions, refer to para. 2-10.

1. Inspect sealing surfaces (7) and (6) on timing gear cover (5) and sealing surfaces (3) and (4) on water

pump adapter plate (1) for deep scratches or dents. Replace either if deeply scratched or dented.

2. Inspect timing gear cover (5) and water pump adapter plate (1) for damage. Replace either

if damaged.

3. Inspect oil filler tube grommet (2) for damage. Replace if damaged.
4. Inspect oil filler tube (9) for damage. Replace if damaged.
5. Inspect oil filler tube cap (8) for damage. Replace if damaged.

2-60